Organic-inorganic hybrid metal halides (OIHMHs) are emerging semiconductor materials that exhibit excellent optoelectronic properties, making them a particularly suitable choice for the development of optoelectronic devices, including lasers, scintillators, photodetectors and light emitting diodes (LEDs)^1-7. In OIHMHs, the valence and conduction bands are primarily formed by the orbital hybridization between metal ions and halogen ions^8-14. As a result, the optical properties of OIHMHs predominantly depend on the specie of metal and halogen ions^{15, 16}.

Due to the typical 5s² electron configuration of Sb³⁺, Sb³⁺-doping has been proven to be an effective method to tune the photophysical properties of OIHMHs by regulating the band structure of metal halides^{17, 18}. A series of Sb³⁺-doped (C₉H₁₅N₃)₂SnCl₈ was reported by Liu et al. using the cooling crystallization method¹⁹. Upon excitation with ultraviolet (UV) light at room temperature, Sb³⁺-doped (C₉H₁₅N₃)₂SnCl₈ displayed red emission centered at 688 nm as well as an increase of photoluminescence quantum yield (PLQY) from 1% to 17.84%, attributed to the enhancement of self-trapped excitons (STEs) emission of Sb³⁺ dopant. Zou et al. have reported a series of zero-dimensional (0D) hybrid metal halides based on Sb³⁺-doped tin(IV) compounds, denoted as (C₁₃H₃₀N)₂SnCl₆:x%Sb²⁰. Among these compounds, (C₁₃H₃₀N)₂SnCl₆:20%Sb exhibits a bright red emission with a PLQY of 80.98% when excited at 380 nm under room temperature. Apart from Sn(IV)-based halides, Sb³⁺ doping has also been employed to enhance the optical property of Cd-based and In-based metal halide. For example, Sb³⁺-doped [NH₃(CH₂)₄NH₃]CdBr₄ exhibited an intense orange emission at approximately 640 nm²¹. This material demonstrated a large Stokes shift of approximately 1.33 eV and a full width at half-maximum (FWHM) of around 0.45 eV. Upon introducing 0.01% Sb doping, the PLQY of [NH₃(CH₂)₄NH₃]CdBr₄ approached near-unity, reaching approximately 97%. Furthermore, 0D MA₄InCl₇ [MA⁺: CH₃NH₃⁺] halides with varying doping levels of Sb³⁺ were prepared using a solvent evaporation method²². MA₄InCl₇ doped with Sb³⁺ exhibits a broadband yellow emission with a FWHM of 180 nm and a high PLQY of 84%. However, because 0D metal halides lead a large distortion of [SbX₆]³⁻ in the excited states, the emission of Sb³⁺ ions in these cases is primarily located in yellow or red range. Compared to all inorganic metal halides, OIHMHs have a soft crystal lattice which is easy to lattice distortion. To date, there are few reports about green emission based on Sb³⁺ in hybrid metal halides. Thus, it is still a challenge to realize the green light emission from such Sb³⁺ doped OIHMHs.

In this work, a new strategy was proposed to control the luminescence of STEs in the inorganic clusters by tuning the hydrogen bond network in the crystal structure. 0D lead-free C₁₀H₂₂N₆InCl₇·H₂O and Sb³⁺-doped C₁₀H₂₂N₆InCl₇·H₂O were synthesized using an antisolvent diffusion method. The hydrogen bonding in C₁₀H₂₂N₆InCl₇·H₂O is mediated by water guest molecules to form a network of hydrogen bonds. When Sb³⁺ is introduced into the metal halides, Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O shows an intense broadband green emission peaking at 540 nm and a high PLQY of 80%. The strong electron-phonon coupling in the 0D crystalline structures of Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O is believed to result in broadband green light emission originating from STEs. The hydrogen bond network limits the structural distortion of the excited state of the inorganic cluster, which plays an important role in the green light emission of Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O. However, breaking the hydrogen bond network with the help of heat causes Sb³⁺-doped C₁₀H₂₂N₆InCl₇ to emit a yellow light. This reversible emission changes can be utilized in information encryption and anti-counterfeiting. Our findings expand the understanding of how the local coordination structure influences the photophysical mechanism in Sb³⁺-doped OIHMHs and provide a novel method to control the STEs emission.

Diantimony trioxide (Sb₂O₃, SP, Macklin), Indium (III) oxide (In₂O₃, 99.99%, Meryer), Hydrochloric acid (HCl, AR, Chongqing Chuandong Chemical), Histamine dihydrochloride (C₅H₁₁N₃Cl₂, 98%, Meryer), Ethanol (99.8%, Boer) and Polymethyl methacrylate (PMMA, Sigma Corp) were used without any further purification.

In₂O₃ (0.069 g, 0.25 mmol) and histamine dihydrochloride (0.368 g, 2.0 mmol) were dissolved in 1.0 mL HCl solution and then filtered into a 20 mL vial to form a clear precursor solution. Then, the vial was placed in a 100 mL vial with 60 mL EtOH inside. The as-prepared solution was sealed and left to stand for ~3 days to afford pale block crystals.

Sb₂O₃ (0.138 g, 0.5 mmol) and histamine dihydrochloride (0.184 g, 1.0 mmol) in 1 mL HCl solution and then filtered into a 20 mL vial to form a clear precursor solution. Then, the vial was placed in a 100 mL vial with 60 mL EtOH inside. The as-prepared solution was sealed and left to stand for ~3 days to afford pale block crystals.

For the synthesis of C₁₀H₂₂N₆In_1-xSb_xCl₇·H₂O, Sb₂O₃/In₂O₃ aqueous solutions with designed compositions were used and the other conditions were kept invariable to obtain the corresponding crystals.

Single crystal XRD (calculated XRD) was carried out on a microfocal spot X-ray single crystal diffractometer (SuperNova, Agilent Technologies, Poland). The powder X-ray diffraction (XRD) patterns were measured using a Cu Kα radiation (XRD-6100, SHIMADZU, Japan). UV-vis Absorption spectra were collected on a UV-vis spectrophotometer (UV-vis: UV-3600, SHIMADZU, Japan). The steady and transient state PL spectroscopies were measured by a fluorescence spectrometer (FLS1000, Edinburgh Instruments Ltd., England). XPS spectra were collected from an ESCA Lab220I-XL. Raman spectra were collected from LabRAM HR Evolution. SEM and EDS mapping were collected from Jieke TESCAN MIRA LMS.

The electronic band structures and wave functions of C₁₀H₂₂N₆InCl₇·H₂O, Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O, Sb³⁺ doped C₁₀H₂₂N₆InCl₇ and C₅H₁₁N₃SbCl₅ were calculated using density functional theory (DFT) implemented on the Vienna ab initio simulation package (VASP). Generalized gradient approximation (GGA) of Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional and pseudopotential with the projector augmented wave (PAW) method were used. The kinetic energy cutoff was set as 400 eV. The electronic wave function was self-consistently converged with energy variation criteria of 10⁻⁵ eV. The atomic structure was relaxed with 2 × 2 × 4 Gamma-center k-point mesh and the atomic force criteria of 0.005 eV/Å (1 Å=10⁻¹⁰ nm). The density of states (DOS) and orbital-resolved partial densities of states (PDOS) were obtained by sampling the Brillouin zone with 2 × 2 × 4 Gamma-center k-point mesh and Gaussian smearing width of 0.05 eV. Band structures are calculated along high symmetry lines of crystal structure with space group P2₁/c and P2₁/n, based on which transition dipole moments are calculated using VASPKIT.

C₁₀H₂₂N₆InCl₇·H₂O single crystals were prepared using an antisolvent diffusion method with C₅H₁₁N₃Cl₂ and In₂O₃ in an aqueous solution of hydrochloric acid (HCl) and ethanol as a slowly-diffusing antisolvent. C₁₀H₂₂N₆InCl₇·H₂O crystalizes in a monoclinic P2₁/c space group, and the structure features In-Cl octahedral units coordinated by six chlorine atoms, as shown in Fig. 1(a) and Table S1. Furthermore, the crystal structure exhibits a hydrogen bonding network among H₂O molecules, C₅H₁₁N₃²⁺ cation and [InCl₆]³⁻ octahedral unit (Fig. S1). As shown in Fig. S2, the obtained powder X-ray diffraction (PXRD) pattern matches well with the simulated pattern, confirming the high crystal purity.

Under 365 nm excitation, C₁₀H₂₂N₆InCl₇·H₂O exhibits blue emission with a PLQY of 9.8% and a corresponding photoluminescence (PL) peak at ~430 nm (Fig. S3). What’s more, the PL decay curve of C₁₀H₂₂N₆InCl₇·H₂O can be fitted with a single exponential function, yielding an average lifetime of 1.8 μs (Fig. S4). To confirm the origin of blue emission, we synthesized the organic hydrochloride counterpart, i.e., C₅H₁₁N₃Cl₂. The C₅H₁₁N₃Cl₂ crystals also show a blue emission centered at 425 nm with a PL lifetime of 1.5 μs (Fig. S5). Thus, it can be reasonably inferred that C₁₀H₂₂N₆InCl₇·H₂O and C₅H₁₁N₃Cl₂ crystals possess a same phosphorescent mechanism, resulting from the C₅H₁₁N₃²⁺ organic cation.

Doping is an effective strategy for introducing outstanding photoelectric properties in semiconductor materials. By partially replacing In₂O₃ with Sb₂O₃, a series of Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O crystals were successfully synthesized. Figure 1(b) illustrates that the C₁₀H₂₂N₆In_1-xSb_xCl₇·H₂O crystals appear as colorless under visible light, resembling the original C₁₀H₂₂N₆InCl₇·H₂O. As the Sb content gradually increases from 0 to 30%, C₁₀H₂₂N₆In_1-xSb_xCl₇·H₂O shows an intense green emission. Subsequently, the photophysical properties of the samples at room temperature were thoroughly investigated. In Fig. 1(c), the PLQY data for the series of samples are plotted as a function of the content of Sb. It is observed that all Sb-doped samples have a higher PLQY than that of the undoped compounds, C₁₀H₂₂N₆InCl₇·H₂O and C₅H₁₁N₃SbCl₅. The incorporated of Sb³⁺ ions enable the formation of [SbCl₆]³⁻ octahedra, which serve as active emission centers in doped crystals. It has been reported that the [SbCl₆]³⁻ octahedra correspond to efficient STEs emission with high PLQY^{23, 24}. Therefore, in this work, the incorporation of Sb³⁺ dopants results in the increase of PLQY up to 80%, and the PLQY value is found to reduce when incorporating a large amount of Sb dopants, which is ascribed to concentration quenching^{25, 26}. C₅H₁₁N₃SbCl₅ crystalizes in the monoclinic P2₁/n space group, forming a 1D organic-inorganic hybrid halides (Fig. S6). C₅H₁₁N₃SbCl₅ has a PL spectrum with broadband characteristics with dominant peaks at 437 nm and 593 nm (Fig. S7). C₅H₁₁N₃SbCl₅ exhibits a low PLQY due to the short distance between Sb ions. The introduction of Sb³⁺ into C₁₀H₂₂N₆InCl₇·H₂O results in a strong green emission centered at 545 nm (Fig. 1(d)). As the amount of Sb was increased, the emission wavelength of C₁₀H₂₂N₆In_1-xSb_xCl₇·H₂O remained constant (Table S2). Additionally, the photoluminescence excitation (PLE) spectra showed two primary peaks which are assigned to the characteristic ¹S₀ to ¹P₁ and ³P₁ transitions of Sb³⁺, respectively. Sb-doping induces an impurity level in the bandgap, leading a reduced bandgap. The PLE spectra shows a redshift trend with increasing the Sb³⁺ concentration due to the Sb-Sb interaction which results in a further reduction of the band gap. As shown in Figs. 1(e) and S8, the PL decay curves for both the doped samples were fitted using a single-exponential function, revealing an average lifetime of 4.3 μs for the doped samples, suggesting that the origin of Sb³⁺ emission.

As illustrated in Fig. 1(f), all the samples exhibit similar XRD patterns. The small shifts towards lower angles observed in these patterns are attributed to the expansion of crystal lattice in doped samples, where the band length of Sb-Cl (1.11 Å) is shorter than that of In-Cl (1.38 Å)²⁷. The successful introduction of Sb dopants into the crystal can be verified through the X-ray photoelectron spectra (XPS) (Fig. S9). As illustrated in Fig. 1(g), the peaks observed at 539.5 and 531.0 eV are attributed to the Sb 3d_3/2 and Sb 3d_5/2 components, respectively. The observation of these peaks serves as a clear confirmation of the presence of Sb in the sample. Furthermore, the introduction of Sb³⁺ results in the shifting of two characteristic peaks of In 3d_3/2 and In 3d_5/2 towards higher binding energies (Fig. 1(h)). Accordingly, both In and Sb in the metal halide frameworks are presented in the form of +3 oxidation state, while Cl is presented in the form of −1 valence state (Fig. S10). As shown in Fig. S11, the energy dispersive spectroscopy (EDS) mapping shows a uniform distribution of In and Sb elements in Sb-doped C₁₀H₂₂N₆InCl₇·H₂O, implying the uniform doping and negligible element segregation.

To identify the origin of the green emission, we conducted a series of experiments. As C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O exhibited the strongest emission, we performed further experiments on this compound. When excitation wavelength increases from 260 to 370 nm, the emission wavelength of C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O remains unchanged. Under different excitation wavelength, the unchanged PL spectra and FWHM values of C₁₀H₂₂N₆In_1-xSb_xCl₇ indicate that its emission originates from the same excited states (Fig. 2(a))^28-30. As shown in Fig. 2(b), the PL intensity of C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O is directly proportional to the excited power density. This implies that its emission may not originate from defects, as evidenced by the absence of a saturated intensity even at high excitation power density³¹.

To gain a better understanding of the origins of the strong green emission observed in C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O, we conducted temperature-dependent PL spectra measurements (Fig. 2(c)). The PL intensity of green emission centered at 545 nm gradually increases when temperature decreases from 300 K to 80 K, which is attributed to the decreased occurrence of nonradiative transitions at the lower temperatures. Figure 2(d) displays the integrated photoluminescence intensity of C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O at varying temperatures. Therefore, we calculated the binding energy (E_a) of the STEs using the Arrhenius equation presented below³²:

$I\left(T\right)=\frac{I_0}{1+A{\text{e}}^{\left(-E_{\text{a}}/k_{\text{B}}T\right)}}\mathrm{,}$(1)

where I₀ represents the integrated PL intensity at 0 K, k_B denotes the Boltzmann constant and A refers to the pre-exponential coefficient. The binding energy of C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O was calculated to be 99.1 meV, as shown in Fig. 2(d). This value is larger than that of traditional 3D perovskites (20–40 meV)^33-35. The calculated E_a is greater than the thermal ionization energy (~26 meV at 300 K), indicating that excitons can remain stable at room temperature. The substantial exciton binding energy contributes to intense radiative recombination, resulting in a high PLQY. We evaluated the electron-phonon coupling effect by examining the relationship between the FWHM of photoluminescence and temperature (Fig. 2(e)). Moreover, we calculate the Huang-Rhys factor (S) and phonon frequency ($\hslash$ω_phonon) using the following formula³⁶:

$FWHM=2.36\sqrt{S}\hslash {\omega }_{\text{phonon}}\sqrt{\text{coth}\frac{\hslash {\omega }_{\text{phonon}}}{2k_{\text{B}}T}}\mathrm{,}$(2)

where k_B denotes the Boltzmann constant and T refers to temperature. The calculated S value and phonon frequency are found to be 39.2 and 17.1 meV, respectively, indicating a strong electron-phonon coupling that can easily generate STEs for C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O. Therefore, the emission mechanism of STEs was confirmed due to the features such as microsecond decay time, large Stokes shift, strong electron-phonon coupling, and broadband emission. Figure 2(f) shows the potential emission mechanism of C₁₀H₂₂N₆In_1-xSb_xCl₇·H₂O. Upon excitation with UV light, the electrons can jump from the ground state to the excited state and subsequently undergo intersystem crossing from a singlet state to a triplet self-trapped state caused by lattice distortion, which results in an effective green emission.

The stability of C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O were investigated. As illustrated in Fig. S12, the PL intensity remains almost unchanged when the samples were irradiated for 420 min under a 365 nm UV irradiation. Figure S13 shows the PL intensity of the C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O, which retains more than 95% of its original PL intensity even upon heating at 80 °C for 420 minutes. After storing the C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O crystals in atmosphere for 30 days, their XRD patterns don’t show obvious change compared with preparing ones, and their emission intensity maintains 90% of the initial value (Fig. S14). All of the above results indicate the good stability of synthesized samples.

As reported by previous studies, Sb³⁺-doped hybrid metal halides predominantly emit yellow or red light^36-38. The green light emission of the samples may result from a robust hydrogen bond network that influences the distortion of the [SbCl₆]³⁻ polyhedron's excited state structure, thereby retaining it at a higher excited state energy level and emitting green light. The thermogravimetric analysis (TGA) curve shows a weight loss from 25 to 140 °C for C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O, correlating with the loss of H₂O in the structure (Fig. S15). After removing the water molecules, C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇ underwent a red shift in PL emission, resulting in yellow emission, as shown in Fig. 3(a). After heating, the emission wavelength of C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O increased from 540 to 570 nm, as depicted in the Fig. 3(b) and 3(c). The breaking of the hydrogen bond network and the existence of larger excited state structural changes of the molecule are responsible for the observed phenomenon. Removing water molecules caused a larger degree of excited state structural distortion of the molecule, which created deeper energy levels of STEs level. This is evidenced by the increase of PL lifetime from 4.3 μs to 4.66 μs due to the greater excited state distortion (Fig. 3(d)). Due to dominant STEs mechanism in Sb³⁺-doped C₁₀H₂₂N₆InCl₇·H₂O, its emission properties can be modulated by excited states induced from distorted structures. After removing the water molecules and breaking the hydrogen bond networks, the Raman intensity of A_1g increases (Fig. S16), corresponding to larger structural distortion. As a result, red shifts of PL spectra and longer PL lifetime are found in Fig. 3(b–d). Additionally, the C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇·H₂O displayed a change in luminescence from yellow to green after absorbing water molecules, which suggests that the process was reversible. Density functional theory (DFT) theoretical calculations revealed that when water molecules were removed, the degree of distortion of [SbCl₆]³⁻ octahedra in the calculated crystal structure was altered (Fig. 3(e)). The distortion degree of the [SbCl₆]³⁻ octahedrons is evaluated using equation^38-40:

${\lambda }_{\text{oct}}=\frac{1}{6}{\displaystyle {\sum }_{i=1}^6}{\left[\frac{d_i-d_0}{d_0}\right]}^2\mathrm{,}$(3)

where d₀ is the average Sb-Cl bond length, d_i are the six individual Sb-Cl bond lengths. The λ_oct of Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O is 3.13×10⁻⁴, while the corresponding values of Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O is 9.22×10⁻⁴ due to the breaking of the hydrogen bond network.

To further investigate the optoelectronic properties of undoped and Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O, we analyzed the band structures through the DFT framework. The crystal structure used in the theory calculation is depicted in Fig. S17. The formation of STEs generally requires low electronic dimensionality. Figure 3(f−h) depict the nearly flat conduction band (CB) and valence band (VB) of undoped and Sb³⁺-doped C₁₀H₂₂N₆InCl₇·H₂O, as well as Sb³⁺-doped C₁₀H₂₂N₆InCl₇, indicating a high degree of electronic state localization that promotes STE formation. After introducing Sb³⁺ ions, the bandgap of the sample decreased from 3.41 eV to 2.90 eV, attributed to the introduction of Sb ion level. This corresponds to the red shift observed in their PLE spectra. After removing water molecules, the bandgap of the sample was 2.83 eV, which may also lead to red shift in luminescence. C₅H₁₁N₃SbCl₅ shows a lower bandgap of 2.58 eV compared to C₁₀H₂₂N₆InCl₇·H₂O, as presented in Fig. S18. As shown in the total and orbital-resolved partial density of states, both the top of valance bands is derived from C and N orbitals, while the bottom of conduction band is dominated by In and Cl orbitals for C₁₀H₂₂N₆InCl₇·H₂O (Fig. 3(i)). Figure 3(j, k) depict that the valence band maximum consists primarily of Sb and Cl states, while the conduction band minimum has a mixed character of In and Cl for both Sb³⁺-doped C₁₀H₂₂N₆InCl₇·H₂O and Sb³⁺-doped C₁₀H₂₂N₆InCl₇.

Based on its unique optical properties, an anticounterfeiting label was fabricated using the as-synthesized C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇. To preventing from water, C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇ was coated in PMMA. As shown in Fig. 4(a), the flowers were coated by C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇@PMMA, while the butterfly and bee were coated by C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇. Both the butterfly and bee emit a yellow emission under 365 nm irradiation before absorbing water and turn to green emission upon 365 nm excitation after absorbing water molecules. An information encryption model, representing “8888”, was constructed by combining C₁₀H₂₂N₆InCl₇·H₂O, C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇ and C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇@PMMA. As shown in Fig. 4(b), the fake number information “8888” is apparent under daylight. Upon excitation with 365 nm UV light, referred to as the first decryption, another fake information “1929” in the template emerges. However, the actual information of “1525” can be observed under 365 nm excitation after absorbing water molecules. As shown in Fig. 4(c), the water-responsive photoluminescent behaviors of C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇ and C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇@PMMA was utilized to construct a dual-input logic gate. According to Fig. 4(d), input A is defined as the sampling signal, with C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇ represented as “1” and C₁₀H₂₂N₆In_0.95Sb_0.05Cl₇@PMMA represented as “0”. Additionally, input B was designated as the environmental signal, where the process of water absorption is represented as “1” and the absence of water absorption is represented as “0”. For the output signal, we defined green emission as “1” and yellow emission as “0”. The logical gate will only be activated when both input A and B are 1, which corresponds to the green emission of the samples after absorbing water molecules. It is worth noting that this doping strategy is applicable to other compounds, providing a new direction for designing optical encryption applications.

In summary, we synthesized C₁₀H₂₂N₆InCl₇·H₂O and Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O using an antisolvent diffusion method. Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O shows strong broadband green light emission peaking at 540 nm and a high PLQY of 80%. The hydrogen bond network limits the structural distortion of the excited state of the inorganic cluster , which plays an important role in the emission of Sb³⁺ doped C₁₀H₂₂N₆InCl₇·H₂O. Breaking the hydrogen bond network causes Sb³⁺-doped C₁₀H₂₂N₆InCl₇·H₂O to emit a yellow light. Therefore, the pattern based on transformed Sb³⁺-doped C₁₀H₂₂N₆InCl₇·H₂O has been achieved and applied in the digital encryption and decryption as well as optical logical “AND” gate. Our findings expand the understanding of how the local coordination structure influences the photophysical mechanism in Sb³⁺-doped metal halides and provide a novel method to control the STE emission.