| 초록 |
Organic-Inorganic hybrid perovskite (OIPVK) is one of strong candidates for the next generation photovoltaic materials. Since Miyasaka group first implemented methylammonium (MA, CH3NH3+) lead tri-iodides (MAPbI3) as a sensitizer of dye sensitized solar cells, there have been dramatic increase of the power conversion efficiency (PCE) of perovskite based solar cells, of which the certified PCE have already reached over 20 %. As the material properties of OIPVKs can be easily manipulated by changing chemical constituents of perovskites, there have been numerous OIPVK varieties. Further enhancement of photon-to-electron conversion efficiency and stability needs understanding of the fundamental physics of materials and devices, which can be addressed by theoretical investigation. Because prior theoretical studies mostly were interested in studying the formation of the charge transition level and the defect chemistry of specialized compositions, especially MAPbI3, a general rule that helps us understand defect formation in various kinds of OIPVKs has not been developed yet. In the first part, I will present how to understand the shallow level defect formations in OIPVKS and when the deep level defects can be generated based on density functional theory calculations. Further improvement of photon conversion efficiency needs the optimization of device structures, which can be studied with the device simulation developed based on carrier transport equation and optics simulation. Screening procedure of materials and device structures based on device simulation for perovskite solar cells will be introduced in the second part. |
