| 초록 |
The general formula AMX3 of inorganic-organic hybrid perovskite materials (A: organic cation, methylammonium (MA) or formamidinium (FA), M: metal, X: halide anion, Br, I) exhibits beneficial properties for high-performance photovoltaic systems such as a suitable band gap (1.5 - 1.4 eV), high absorption coefficient (104 - 105 cm-1), low exciton binding energy (＜ 50 meV), and long charge-carrier diffusion length (~175 µm). In addition, these materials exhibit easy crystallization at low-temperature by solution processing, resulting in their low cost. Based on above distinct properties of perovskite materials, we have designed a new photovoltaic platform for efficient perovskite solar cells (PSCs). The performance have been remarkably increased to more than 22 % by introducing a mediator to retard the rapid crystallization between organic cations and PbI2, and manipulate the chemical composition of the perovskites via solvent engineering, intramolecular exchange process. |
