Based on the photoelectric generation and electroluminescence characteristics of photodiodes, the photoelectric to electro-optical conversion characteristics can be realized. Therefore, solar cells and light-emitting diodes being made by various semiconductor photoelectric materials have attracted great interest in recent years. However, the current photoelectric conversion devices require low manufacturing cost, high photovoltaic performance and energy saving and environmental protection characteristics. So a new photovoltaic material is needed to be found to meet the above requirements. Metal halide perovskite, represented by MAPbI3, is an ideal material for new optoelectronic devices because of its advantages such as simple growth process, wide spectral absorption range and high defect tolerance. The working principle of photoelectric to electro-optical conversion in two kinds of photoelectric devices is analyzed.