
Search by keywords or author
Journals >Journal of Synthetic Crystals
Export citation format
[in Chinese]
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1 (2022)
[in Chinese]
[in Chinese]
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1515 (2022)
[in Chinese]
[in Chinese]
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1519 (2022)
[in Chinese]
[in Chinese]
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1523 (2022)
Optical Superlattice: from Bulk to Thin Film
CHEN Haiwei, HU Xiaopeng, and ZHU Shining
Optical superlattice is a nonlinear optical material based on the quasi phase matching technology. Optical superlattice with different microstructures enabled by ferroelectric domain engineering can efficiently and flexibly realize nonlinear frequency conversions as well as multi-dimensional manipulation of the light fOptical superlattice is a nonlinear optical material based on the quasi phase matching technology. Optical superlattice with different microstructures enabled by ferroelectric domain engineering can efficiently and flexibly realize nonlinear frequency conversions as well as multi-dimensional manipulation of the light field. The host material of optical superlattice has been undergoing the development from bulk to thin film. With the breakthrough of the fabrication techniques of the two material platforms, diverse important applications have been spawned, such as laser frequency conversion technology, nonlinear light field manipulation and multi-functional integrated photonic chips..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1527 (2022)
“Amorphous” Crystals: Crystals Formed from Amorphous Constituents
WANG Lin, and TIAN Yongjun
Amorphous crystals, a family of crystals consist of amorphous building blocks were discovered at about ten years ago. The discovery challenged our understanding of the inherent disorder that can be presented in a crystal, and have attracted a lot of research attentions. Many progresses have been made in this field duriAmorphous crystals, a family of crystals consist of amorphous building blocks were discovered at about ten years ago. The discovery challenged our understanding of the inherent disorder that can be presented in a crystal, and have attracted a lot of research attentions. Many progresses have been made in this field during the past ten years. This review will serve as a summary of the progresses made and hopefully could promote more research efforts and push this research field forward fast..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1535 (2022)
From Mineral Gems to Photoelectric Functional Crystals——A Interpretation of Mr. Jiang Minhua’s Crystal Ode
YANG Jinfeng, SUN Jun, QIN Juan, LI Qinglian, SHANG Jifang, ZHANG Ling, and XU Jingjun
The crystals are beautiful and useful, and the structure is harmonious and orderly. Photoelectric functional crystal can realize the interconversion of optical and electric energy, and occupy an important position in the high-tech fields of microelectronics, optoelectronics, communications, aerospace and modern militarThe crystals are beautiful and useful, and the structure is harmonious and orderly. Photoelectric functional crystal can realize the interconversion of optical and electric energy, and occupy an important position in the high-tech fields of microelectronics, optoelectronics, communications, aerospace and modern military technology. People’s understanding of crystals is derived from natural minerals. From the discovery of mineral crystals to the artificial growth and application of photoelectric functional crystals, great progress has been made in crystal types, crystal quality, growth theory, growth technology and application. The development process from mineral gem to crystallography is briefly described, the development process of several kinds of photoelectric functional crystals such as piezoelectric crystal, electro-optic crystal, laser crystal, nonlinear optical crystal and scintillation crystal is introduced, and research progress on crystal growth is summarized in this paper..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1541 (2022)
High-Power Laser and Ultra-High Thermal Conductivity Laser Crystals
ZHANG Zhen, FAN Zhongwei, and SU Liangbi
The development of high-power solid state laser technology is a course of struggling against the "waste heat" generated with lasering. The most critical issue for the development of high-power solid-state lasers is how to suppress the thermal effect on the beam quality under high-power operating conditions. TThe development of high-power solid state laser technology is a course of struggling against the "waste heat" generated with lasering. The most critical issue for the development of high-power solid-state lasers is how to suppress the thermal effect on the beam quality under high-power operating conditions. To improve this adverse effect researchers invented heat capacity laser, thin-film laser, slab laser and fiber laser. These new designs of lasers based on novel form of gain medium combined with advanced heat dissipation technology have enhanced the output power to about one hundred kilowatts. However, the thermal properties of the solid state gain medium have become the critical bottleneck restricting further breakthroughs in laser power. Therefore, it is of great significance to explore the novel laser crystal materials with ultra-high thermal conductivity. This paper introduces the basic principles of the above four lasers and their research progress in high-power lasers. From the perspective of improving the thermal conductivity of gain medium materials, the existing methods and related results are analyzed and summarized. The research on ultra-high thermal conducting laser crystals and the development of high-power laser technology are also prospected..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1560 (2022)
Development of Rare-Earth Ion Doped Fluoride Laser Crystal
ZHAO Chengchun, ZHANG Peixiong, LI Shanming, FANG Qiannan, XU Min, CHEN Zhenqiang, and HANG Yin
As a laser gain media, rare-earth ion doped fluoride crystals have advantages of high transparency in a wide wavelength range, low phonon-energy, long fluorescence lifetimes and negative thermal dependence of refractive index, and can emit lasers from ultraviolet to mid-infrared. In this paper, the research progress ofAs a laser gain media, rare-earth ion doped fluoride crystals have advantages of high transparency in a wide wavelength range, low phonon-energy, long fluorescence lifetimes and negative thermal dependence of refractive index, and can emit lasers from ultraviolet to mid-infrared. In this paper, the research progress of our group in the growth, optical and laser properties of rare-earth ion doped fluoride crystals (LiLuF4, LiYF4, BaY2F8, LaF3, PbF2, CeF3) are reviewed. The rare-earth ion co-doping effects of sensitization, deactivation, energy level coupling and emission spectra broadening are introduced, and the development trend of rare-earth ion doped fluoride laser crystal in the future is prospected..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1573 (2022)
Nonlinear Optical Crystals with Planar Conjugated Configuration
FAN Huixin, LUO Min, and YE Ning
Ultraviolet nonlinear optical (NLO) crystals are the key materials to realize the development of ultraviolet solid-state lasers. At present, NLO crystals mainly rely on borate crystals, but the existing NLO crystals could not meet the applications fully. While it is increasingly difficult to find new NLO crystals, so iUltraviolet nonlinear optical (NLO) crystals are the key materials to realize the development of ultraviolet solid-state lasers. At present, NLO crystals mainly rely on borate crystals, but the existing NLO crystals could not meet the applications fully. While it is increasingly difficult to find new NLO crystals, so it is particularly urgent to develop new material systems. From the relationship between borate structures and optical and nonlinear optical properties, it can be known that borates which containing planar conjugated groups have the characteristics of large frequency doubling coefficient, suitable birefringence and short UV cut-off edge. Group with planar conjugated configuration is the core functional unit of borate NLO crystals. The study of expanding planar conjugated groups based on geometric configuration is an important idea for exploring new systems of UV nonlinear optical materials. Based on these, our team proposes to expand the exploration scope of UV NLO crystals by studying CO3, NO3, C(NH2)3 groups with planar triangular conjugated structures and HC3N3O3, H2C4N2O3 groups with planar six-member ring conjuated structures. The research results obtained by our team in the exploration of UV crystals of carbonate, nitrate, guanidine, cyanurate and barbiturate in recent years are mainly introduced in this paper..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1588 (2022)
Development of A7MIIRE2(B5O10)3 Series Ultraviolet Nonlinear Optical Crystals
HE Nan, GONG Pifu, and LIN Zheshuai
Rare earth nonlinear optical (NLO) borates have attracted much attention due to their important applications in the field of laser technology. It is known that the trivalent rare earth ions (RE3+), such as Y3+, Sc3+, and Lu3+, usually have wide ultraviolet transmission range since their d-d and f-f electronic transitioRare earth nonlinear optical (NLO) borates have attracted much attention due to their important applications in the field of laser technology. It is known that the trivalent rare earth ions (RE3+), such as Y3+, Sc3+, and Lu3+, usually have wide ultraviolet transmission range since their d-d and f-f electronic transitions are effectively suppressed. Meanwhile, the distorted [REOn] polyhedra can significantly enhance the NLO effect. A7MIIRE2(B5O10)3 series (RE=rare earth, A=alkaline metal, M=divalent metal) are an important family of rare earth borates, in which A, M and RE sites can be flexibly occupied. Till now, dozens of A7MIIRE2(B5O10)3 compounds have been synthesized through chemical element substitution. Most of their transmission cut-off edges are located in the ultraviolet band, even in the deep ultraviolet band down to 200 nm, and their NLO effects are 0.4~2.1 times of KDP, showing its potential as promising NLO materials in ultraviolet/deep ultraviolet region. This article summarizes the recent progress of A7MIIRE2(B5O10)3 family by investigating the relationship between their microstructure and optical properties, from which the effects of different atomic sites on NLO properties are pointed out. This work would be beneficial to the future development of rare earth NLO borates..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1598 (2022)
Research Progress of Huntite Family Nonlinear Optical Crystals
ZHANG Yutong, ZHU Mengqi, WANG Biao, JIA Xinhui, LI Jing, and WANG Jiyang
Self frequency doubling crystal is a kind of crystal that integrates laser and nonlinear optical effect, which can realize wavelength conversion, amplitude modulation, switch, memory and other functions, and has become widely used in photoelectronic, optical communication, laser and other fields. However, the existing Self frequency doubling crystal is a kind of crystal that integrates laser and nonlinear optical effect, which can realize wavelength conversion, amplitude modulation, switch, memory and other functions, and has become widely used in photoelectronic, optical communication, laser and other fields. However, the existing crystals such as Nd∶LiNbO3(Nd∶LN), Nd∶Na3La9O3(BO3)8(Nd∶NLBO), Nd∶La2CaB10O19(Nd∶LCB) have limited the further applications due to their inherent photorefractive effect, low second harmonic generation (SHG) output power, poor optical homogeneity and other shortcomings, so it is necessary to develop new laser self frequency doubling crystals. Due to the large nonlinear optics (NLO) coefficient, difficult to deliquesce, excellent optical, mechanical properties and so on, hunitite family borate crystals have become the focus of research in recent decades. In this paper, the crystal structure, growth methods, properties and development trend and other aspects of huntite family REM3(BO3)4 (RE is rare earth elements La-Lu and Y; M is Al, Ga, Sc) and LaxREyScz(BO3)4(RE=Gd, Y, Nd, Lu, Sm, Tb; x+y+z=3) co-substituted borate nonlinear optical crystals are introduced emphatively. The differences of ultraviolet (UV) cut-off edge, optical properties and nonlinear properties of crystals grown by different fluxes, atmospheres and methods are compared. By improving the growth technology and doping elements, self-frequency-doubled (SFD) crystals with good optical properties, remarkable nonlinear properties and extensive market application prospects can be obtained..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1608 (2022)
Photorefractive Effect of Lithium Niobate Crystals
ZHENG Dahuai, ZHANG Yuqi, WANG Shuolin, LIU Hongde, LIU Shiguo, KONG Yongfa, BO Fang, and XU Jingjun
Lithium niobite (LiNbO3, LN) is a kind of multi-functional artificial crystal, which is called “optical silicon”. Recently, the rapid development of integrated photonics based on LN film (LNOI) has a great tendency to turn “optical silicon” into reality. High integration means high local intensity density, so the photoLithium niobite (LiNbO3, LN) is a kind of multi-functional artificial crystal, which is called “optical silicon”. Recently, the rapid development of integrated photonics based on LN film (LNOI) has a great tendency to turn “optical silicon” into reality. High integration means high local intensity density, so the photorefractive effect of LN crystal can’t be ignored any more. Photorefractive effect, short for photoinduced refractive index change, which is an important part of nonlinear optics. In this paper, the discovery and mechanism of photorefractive effect, the regulation of photorefractive effect by different dopants and doping combinations are reviewed. The photorefractive characteristics of bismuth-magnesium double-doped LN crystal, related theoretical and experimental results are mainly introduced. The characteristics and applications of LN photorefractive waveguide, optical soliton, and the photorefractive effect in LNOI-based integrated photonics devices are summarized. The future research trends are also prospected. It is expected that China will make full use of the advantages of LN photorefraction research and LNOI industrialization and occupy the advantage in the competition of photonics chips..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1626 (2022)
Research Progress on the Growth and Property Optimization of Relaxor Ferroelectric Single Crystals
LIU Yangbin, LI Qian, XIAO Ruoyu, XU Zhuo, and LI Fei
Relaxor ferroelectric single crystals with perovskite (ABO3) structure possess excellent electromechanical coupling properties and are considered as the key materials of next-generation medical ultrasound transducers, high-precision piezoelectric actuators, and underwater acoustic transducers. According to the existingRelaxor ferroelectric single crystals with perovskite (ABO3) structure possess excellent electromechanical coupling properties and are considered as the key materials of next-generation medical ultrasound transducers, high-precision piezoelectric actuators, and underwater acoustic transducers. According to the existing fundamental science and material preparation issues in relaxor ferroelectric crystals, this manuscript reviews the research progresses on the crystal growth and property optimization of relaxor ferroelectric singles in recent years. This review covers the following aspects: new crystal growth methods for enhancing the uniformity of composition and properties; new methods to improve the piezoelectric properties of relaxor ferroelectric single crystals; the control of ferroelectric domain structure to achieve high-light transmittance of relaxor ferroelectric crystals; the application of high-performance relaxor ferroelectric single crystals in the field of electro-optical technology..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1643 (2022)
Research Progress and Application of Magneto-Optical Thin Films Based on RIG
ZHU Senyin, ZHANG Hanxu, WANG Xianjie, HUANG Zhanjun, and SONG Bo
With the development of optical communication technology and photonic integrated circuits, non-reciprocal devices have been widely studied and applied as an important part of optical communication systems. Magneto-optical isolators and circulators based on magneto-optical effect are currently the most widely used non-rWith the development of optical communication technology and photonic integrated circuits, non-reciprocal devices have been widely studied and applied as an important part of optical communication systems. Magneto-optical isolators and circulators based on magneto-optical effect are currently the most widely used non-reciprocal devices. In order to integrate non-reciprocal devices into silicon wafers, magneto-optical thin films with comparable performance to bulk magneto-optical materials need to be prepared. In the near-infrared band (1 550 nm), rare earth iron garnet (RIG) represented by yttrium iron garnets (Y3Fe5O12, YIG) has excellent magneto-optical effects and become one of the most promising magneto-optical materials. It is found that doping with rare earth ions can effectively improve the magneto-optical properties of YIG thin films, especially Bi3+ and Ce3+ doped YIG exhibit giant Faraday effect. In this paper, the Faraday effect principle is briefly introduced, three common growth methods of RIG magneto-optical thin films and their research progress in recent years are reviewed, and the application of RIG magneto-optical thin films in optical isolators and circulators are summarized. Finally, the future development trend of magneto-optical films is prospected..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1659 (2022)
Dislocations in 4H Silicon Carbide Single Crystals
YANG Guang, LIU Xiaoshuang, LI Jiajun, XU Lingbo, CUI Can, PI Xiaodong, YANG Deren, and WANG Rong
Owing to the advantages of wide bandgap, high carrier mobility, high thermal conductivity and high stability, 4H silicon carbide (4H-SiC) has shown great potential in high-power electronics, RF/microwave electronics and quantum information. Although the industrialization of 6-inch 4H-SiC single crystals substrate and hOwing to the advantages of wide bandgap, high carrier mobility, high thermal conductivity and high stability, 4H silicon carbide (4H-SiC) has shown great potential in high-power electronics, RF/microwave electronics and quantum information. Although the industrialization of 6-inch 4H-SiC single crystals substrate and homoepitaxial films have been achieved after decades of development, the total dislocation density of 4H-SiC single crystal is still the order of magnitude of 103~104 cm-3, which poses great challenge to the realization of the full potential of 4H-SiC. This review introduces the classification and basic properties of dislocations in 4H-SiC single crystal. The mechanism of generation, transformation and annihilation of dislocation between different types of dislocations during the growth, wafering, and the homoepitaxy of 4H-SiC single crystals are systematically reviewed. By introducing the characterization and identification of dislocations in 4H-SiC, the effect of dislocations on the properties of 4H-SiC is shown, and the device performance and reliability are also presented..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1673 (2022)
Research Progress of AlN-Based Filters: Materials, Devices and Applications
OUYANG Peidong, YI Xinyan, LUO Tianyou, WANG Wenliang, and LI Guoqiang
In the era of 5G communication, bulk acoustic wave (BAW) filters have become an effective solution to achieve high-performance radio frequency (RF) filtering. In the current environment where film bulk acoustic resonator (FBAR) technology (the most mature BAW technology) and patents are held by a few companies, it is eIn the era of 5G communication, bulk acoustic wave (BAW) filters have become an effective solution to achieve high-performance radio frequency (RF) filtering. In the current environment where film bulk acoustic resonator (FBAR) technology (the most mature BAW technology) and patents are held by a few companies, it is essential to make breakthroughs in piezoelectric film growth and device preparation, to form a unique BAW device technology route. This paper reviews the AlN thin film growth, the development of AlN in BAW filter devices, and the preparation and application of AlN-based BAW devices. With the efforts of domestic researchers, the single-crystalline AlN bulk acoustic resonator (SABAR) device has further improved the performance of BAW devices through independent innovation in the material growth method and preparation process. Moreover, it also brought a new route to eliminate the “neck sticking” problem to the RF filter industry constrained by foreign countries..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1691 (2022)
Research Progress on Indium Selenide Crystals and Optoelectronic Devices
ZHAO Qinghua, ZHENG Dan, CHEN Peng, WANG Tao, and JIE Wanqi
Since the discovery of graphene in 2004, the research and application of two-dimensional (2D) materials have received great attention and developed rapidly. Abundant band gap structures, unique optoelectronic properties, and van der Waals surfaces without dangling bonds greatly broaden the design dimensions of semicondSince the discovery of graphene in 2004, the research and application of two-dimensional (2D) materials have received great attention and developed rapidly. Abundant band gap structures, unique optoelectronic properties, and van der Waals surfaces without dangling bonds greatly broaden the design dimensions of semiconducting electronics and optoelectronics. Among them, the two-dimensional indium selenide, as one of the most promising candidates for future high-mobility optoelectronic devices, it has been recognized as “the ‘golden middle’ between silicon and graphene” by Nobel Prize winner Andre Geim. However, the research on two-dimensional indium selenide material has only been less than ten years, and the understanding of crystals fabrication and device application is still insufficient. This work mostly focuses on the development of indium selenide materials and the research status of its electronic and optoelectronic devices. In addition, considering that the present research on 2D indium selenide are mostly based on mechanical exfoliation of InSe bulks, the development of the crystal structure characterization and crystals fabrication are traced in this paper, then the state-of-the-art on the preparation and performance characterization of two-dimensional indium selenide are further summarized, and the influence of device geometries, material fabrication method and other factors on the electrical transport performance of 2D indium selenide field effect transistors and photodetectors are further discussed, and ended with analysis of the opportunities and challenges for future indium selenide based applications..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1703 (2022)
Research Progress of Ⅲ-Ⅵ Group InSe Semiconductor Crystal Growth
HE Feng, BAI Xudong, LU Xinyu, ZHENG Shuying, LI Rongbin, LIU Xuechao, WEI Tianran, SHI Xun, and JIN Min
Ⅲ-Ⅵ group InSe crystal is a very important compound semiconductor material, which is widely used in the fields of high-performance nano electronic devices, infrared light detection, photoelectric devices and flexible electronics. The development of In-Se phase diagram is briefly reviewed. InSe has incongruent melting cⅢ-Ⅵ group InSe crystal is a very important compound semiconductor material, which is widely used in the fields of high-performance nano electronic devices, infrared light detection, photoelectric devices and flexible electronics. The development of In-Se phase diagram is briefly reviewed. InSe has incongruent melting characteristics that can be obtained by peritectic reaction from the quasi stoichiometric or non-stoichiometric solution, and the mole ratio of In/Se has an important influence on the productivity of InSe. In order to prepare InSe crystal, several techniques have been adopted in the past, such as vertical Bridgman method, Czochralski method, horizonal gradient freeze method, low temperature liquid phase method and vapor transfer method. In order to better understand the development of InSe crystal growth, this review summarizes the process principle, technical points, production of these techniques, and discsuses their advantages and disadvantages. It is shown that the vertical Bridgman method has become a mainstream method for preparing high quality and large size InSe crystals by virtue of the simple apparatus and feasible operation. The horizonal gradient freeze method is a special way for growing ε-InSe crystal, which would play a role of supplement to the vertical Bridgman method in the research and application of new material in the future..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1722 (2022)
Advance in Theory and Technology of Rapid Growth of Large-Size Crystals
LIU Feng, CHEN Kunfeng, PENG Chao, and XUE Dongfeng
“How to break through the preparation theory and technology of large size crystal materials” is one of the top ten frontier scientific questions released by China Association for Science and Technology in 2021, which revealing the crystal growth mechanism and breaking through the key growth technologies are the two tre“How to break through the preparation theory and technology of large size crystal materials” is one of the top ten frontier scientific questions released by China Association for Science and Technology in 2021, which revealing the crystal growth mechanism and breaking through the key growth technologies are the two trends of the development of large size functional crystals. At the atomic or molecular scale, the crystal growth can be described as a thermal activation process with a barrier or an ultrafast growth of crystal without barrier, which is related to the specific system and growth direction. Based on the properties of interface, the smooth interface grown by the way of step expansion, and the rough interface has no obvious solid-liquid stratification, and the growth can be completed by local atomic solidification. The advances of growth theory and technology for the large-size crystals in recent years have been summarized from three aspects: model, technology of growth and its application and the application of molecular dynamics in crystal growth. At present, there are many methods to grow large-size crystals, but the crystal quaility is poor and performance is unstable. The reasons are that the existing technology do not take the micro-mechanism of crystal growth into consideration, and the relationship among crystal growth mechanisms and external factors such as temperature and flow rate are not clear. Using machine learning force field and molecular dynamics simulation method to establish solid-liquid interface and to simulate crystal growth would be an effective way to explore the micro-mechanism of crystal growth..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1732 (2022)
Growth of 8 Inch Conductivity Type 4H-SiC Single Crystals
YANG Xianglong, CHEN Xiufang, XIE Xuejian, PENG Yan, YU Guojian, HU Xiaobo, WANG Yaohao, and XU Xiangang
8 inch 4H-SiC seed was obtained by physical vapor transport (PVT) method with expansion of boule diameter from 6 inch. 8 inch conductivity type 4H-SiC crystal has been grown using 8 inch seed. 8 inch 4H-SiC substrate with a thickness of 520 μm was processed. Wafers were characterized by Raman spectroscopy, automatic mi8 inch 4H-SiC seed was obtained by physical vapor transport (PVT) method with expansion of boule diameter from 6 inch. 8 inch conductivity type 4H-SiC crystal has been grown using 8 inch seed. 8 inch 4H-SiC substrate with a thickness of 520 μm was processed. Wafers were characterized by Raman spectroscopy, automatic microscope scanning, contactless resistivity measurement and high resolution X-ray diffraction (HRXRD). The polytype of whole wafer with the uniform color is 4H-SiC without other polytypes inclusions. Micropipe density is less than 0.3 cm-2. The resistivity range is from 20 mΩ·cm to 23 mΩ·cm, with an average value of 22 mΩ·cm. The full width at half maximum of the rocking curve of (004) diffraction peak is 32.7″, which indicates the good crystalline quality of the crystal..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1745 (2022)
Growth and Properties of 4 Inch β-Ga2O3 Single Crystal
MU Wenxiang, JIA Zhitai, and TAO Xutang
4 inch β-Ga2O3 single crystals were grown by edge-defined film-fed growth (EFG) method in this work. The crystalline phase, crystal quality, defects, optical and electrical properties were studied. The Laue diffraction patterns is distinct and consistent which conformed to the characteristic of β-Ga2O3. The full width 4 inch β-Ga2O3 single crystals were grown by edge-defined film-fed growth (EFG) method in this work. The crystalline phase, crystal quality, defects, optical and electrical properties were studied. The Laue diffraction patterns is distinct and consistent which conformed to the characteristic of β-Ga2O3. The full width at half maximum (FWHM) of rocking curve of (400) plane is 57.57″. The density of etch pit by chemical corrosion is 1.06×104cm-2. The ultraviolet cut-off edges of the (100) plane is 262.1 nm and the optical bandgap is 4.67 eV. The electron concentration of the unintentionally doped crystal measured by C-V test is 7.77×1016 cm-3..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1749 (2022)
[in Chinese]
[in Chinese]
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1754 (2022)
Effect of Heating Power and Porosity of Stacked Silicon on Seed Crystal Melting during Quasi-Single Crystalline Silicon Casting Process
SUN Yinglong, ZHENG Lili, and ZHANG Hui
Based on the porous media model, a simplified model of stacked silicon was established to consider stacked porosity and melting deformation. This model was applied to numerical simulate the stacked silicon melting process of the quasi-single crystalline silicon casting system for photovoltaic solar application. EffectsBased on the porous media model, a simplified model of stacked silicon was established to consider stacked porosity and melting deformation. This model was applied to numerical simulate the stacked silicon melting process of the quasi-single crystalline silicon casting system for photovoltaic solar application. Effects of the power ratios of side/top heaters, stacked porosity, and total power of heaters on the seed crystal melting process were studied. The results show that the melting time of silicon and the melting ratio of seed crystal depend on the power ratio of side/top heaters. Reducing the power ratio and the porosity is beneficial to the retention of seed crystal, nevertheless, it changes the interface shape after seed crystal melting. The impurities can gather in the concave region of the interface after seed crystal melting. Such distribution of impurities affects the quality of subsequent grown crystals. When the total power of the heater is below the critical value, the interface shape after seed crystal melting also changes near the edge of the crucible wall. This change can lead to uneven nucleation, which is not desirable for the production of quasi-single crystalline silicon. Therefore, the process parameters under the actual working conditions shall be configured according to the contour map, which is determined by the power ratio of side/top heaters, stacked porosity, the total power of heaters, the melting ratio of the seed crystal, and the melting state of the seed crystal..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1755 (2022)
Remote Epitaxy of Ge Nanorods Through Graphene
XIE Jinglong, YUAN Guowen, LIAO Junjie, PAN Rui, FAN Xing, ZHANG Weiwei, YUAN Ziyuan, LI Chen, GAO Libo, and LU Hong
Remote epitaxy has drawn great attention as it overcomes the limitations of conventional epitaxy that need the lattice and thermal diffusion coefficient matching well. Indeed, the remote interaction through graphene can get the high-quality semiconductor materials, and it also can form the freestanding membranes by relRemote epitaxy has drawn great attention as it overcomes the limitations of conventional epitaxy that need the lattice and thermal diffusion coefficient matching well. Indeed, the remote interaction through graphene can get the high-quality semiconductor materials, and it also can form the freestanding membranes by releasing from the substrates. Although the Ⅲ-Ⅴ and Ⅲ-nitride compound semiconductors have successfully remote epitaxial grown on graphene, the Ⅳ group semiconductors are rarely reported. Herein, the semiconductor germanium nanorods (NRs) on monolayer graphene (MLG) substrate were successfully remote epitaxy grown using molecular beam epitaxy in this paper. Furthermore, the process of growth, lifting off and transferring was studied. Results show that the Ge NRs oriented[111]c nucleated and grew along the wrinkles of graphene and the atomic steps of Cu-Ni substrate. With the growth temperature increasing, the density and height of Ge NRs decrease gradually. However, the diameter of Ge NRs has little change between 55 nm to 65 nm. Meanwhile, the Ge nanorods by self-assembly are strain free. The surface density of Ge nanorods is improved significantly by introducing few Sn to form GeSn nanorods. Meanwhile, we successfully lifted off the Ge NRs and then transferred to the Si substrate, providing a novel strategy for the hetero-integration. This work provides a foundation for future research into the remote epitaxy of group Ⅳ semiconductors, more importantly, the technique is closely relevant to the hetero-integration for advanced devices..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1769 (2022)
Comparative Study on the Quality of HTHP and CVD Single Crystal Diamond Substrates
YANG Yiqiu, HAN Xiaotong, HU Xiufei, LI Bin, PENG Yan, WANG Xiwei, HU Xiaobo, XU Xiangang, WANG Dufu, LIU Changjiang, and FENG Zhihong
The comparative study of high temperature and high pressure (HTHP) and chemical vapor deposition (CVD) single crystal diamonds was carried out. HTHP Ⅰb, HTHP Ⅱa, and CVD (100) single crystal diamonds were investigated by HRXRD, Raman and lattice distortion detector. The results of HRXRD and Raman demonstrate that the cThe comparative study of high temperature and high pressure (HTHP) and chemical vapor deposition (CVD) single crystal diamonds was carried out. HTHP Ⅰb, HTHP Ⅱa, and CVD (100) single crystal diamonds were investigated by HRXRD, Raman and lattice distortion detector. The results of HRXRD and Raman demonstrate that the crystal quality of HTHP Ⅱa single crystal diamond is close to that of natural diamond. The full width at half maximum of rocking curve and Raman are respectively 0.015° to 0.018° and 1.45 cm-1 to 1.85 cm-1. The optical birefringence images measured by lattice distortion detector show that there are two kinds of stress-induced birefringence distribution in HTHP Ⅱa single crystal diamond, one is not obvious, the other is symmetrically radiated along the direction of <110>, and there is no lattice distortion in other regions. The strain structures of HTHP Ⅰb and CVD (100) single crystal diamond are relatively dispersed with complex lattice distortion. Furthermore, the defects of (100) plane of three types of single crystal diamond were analyzed by plasma etching method. The results show that the dislocation density of HTHP Ⅱa diamond is the lowest among the three types, which is only 1×103 cm-2. The research work provides experiment support for selecting the substrate to prepare high-quality and large-size CVD single crystal diamond..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1777 (2022)
Optical Transition Intensity Calculation of High-Density Scintillator Nd∶GdTaO4 and Nd∶LuTaO4
ZHANG Qingli, SUN Guihua, LUO Jianqiao, HE Yi, CHEN Yingying, GAO Jinyun, DOU Renqin, LIU Wenpeng, WANG Xiaofei, DING Shoujun, ZHANG Deming, and SUN Yu
GdTaO4 and LuTaO4 are heavy scintillators with fast decay fluorescence. The photoluminsecence spectra of M phase Nd∶GdTaO4 and M′ phase Nd∶LuTaO4 excited by a laser diode (LD) of 808 nm were fitted with the full-profile fitting method, and the transition intensity parameters Akt,p were determined. Under the excitation GdTaO4 and LuTaO4 are heavy scintillators with fast decay fluorescence. The photoluminsecence spectra of M phase Nd∶GdTaO4 and M′ phase Nd∶LuTaO4 excited by a laser diode (LD) of 808 nm were fitted with the full-profile fitting method, and the transition intensity parameters Akt,p were determined. Under the excitation of 808 nm LD laser, the population ratio between the upper and low crystal field energy levels of 4F3/2 for Nd3+ in GdTaO4 is near to 1, but in LuTaO4 is 1.30 and 1.41, which indicates that the relaxation rate between two crystal field energy levels is nearly equal to the excitation rate of LD. The Judd-Ofelt transition intensity parameters Ωt were calculated with Akt,p, and the transition probabilities from 2P3/2 of Nd3+ in GdTaO4 and LuTaO4 were computed, which indicates that the fast decay fluorescence of several hundred nanoseconds of Nd3+ in GdTaO4 and LuTaO4 is caused by the high nonradiative transition..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1785 (2022)
Influence of Poling Methods on the Properties of PZT-4 Piezoelectric Ceramics
HU Yudong, WANG Yuequn, KONG Shuyan, ZHANG Wenjie, YANG Xiaoming, WANG Zujian, SU Rongbing, LONG Xifa, and HE Chao
Pb(Zr1-xTix)O3(PZT) piezoelectric ceramics have been used extensively due to their comprehensive performance. Compared with direct current poling (DCP) and alternating current poling (ACP) methods, the combining DCP and ACP method can further improve the piezoelectric properties of relaxor-based ferroelectric single crPb(Zr1-xTix)O3(PZT) piezoelectric ceramics have been used extensively due to their comprehensive performance. Compared with direct current poling (DCP) and alternating current poling (ACP) methods, the combining DCP and ACP method can further improve the piezoelectric properties of relaxor-based ferroelectric single crystals. Here, the dielectric and piezoelectric properties of DCP, ACP, and ACP+DCP PZT-4 piezoelectric ceramics. The optimal poling conditions of DCP, ACP, and ACP+DCP were studied. The d33 of ACP+DCP PZT-4 piezoelectric ceramics reported in this paper is 350 pC/N, which is 15% and 9% higher than that of DCP (305 pC/N) and ACP (320 pC/N) samples. The strain value under electric field of the ACP PZT-4 ceramic (0.08%) is higher than that of the DCP sample (0.05%), indicating that ACP can effectively improve the strain value of PZT-4 ceramics. However, the increased hysteresis of the strain curve for ACP sample is not conducive to application. The effect of ACP on hard PZT piezoelectric ceramics needs to be further explored..
Journal of Synthetic Crystals
- Publication Date: Nov. 18, 2022
- Vol. 51, Issue 9-10, 1794 (2022)