Influence of Functional Diamino Organic Cations on the Stability, Electronic Structure, and Carrier Transport Properties of Three-Dimensional Hybrid Halide Perovskite

In recent years, organic–inorganic hybrid halide perovskites have attracted wide attention due to their excellent photoelectric properties. MAPbI3 and FAPbI3 have particularly shown great application prospects. However, due to the low thermal and chemical stability of these monoamino organic cation 3D perovskites, the durability of the devices in which they are used is affected. In this paper, an inorganic skeleton was introduced to functional diamino organic cations (PDA and DAB) to obtain more stable diamino 3D perovskites (PDAPbI4 and DABPbI4). For comparison with the 3D perovskites, two monoamino perovskites with the same molecular chain length ((PT)2PbI4 and (MBA)2PbI4) were also designed. The geometrical structures, thermodynamic stability, electronic properties, transport properties, and optical absorption properties of the four perovskites were calculated by the first-principles method. The results demonstrate that diamino organic cations can, to a certain extent, provide favorable channels for carrier migration, especially for carrier migration between Pb–I inorganic layers, and increase the coupling effect between Pb–I inorganic layers. In addition, the excellent optical absorption properties of diamino organic cation 3D perovskites in the solar irradiation range can contribute to the design and synthesis of more effective and stable organic–inorganic perovskite optoelectronic devices in the future.