Where: Seminar Room - 1st floor
Presented by: Germà Garcia-Belmonte
Although metal and organic halide perovskite solar cell has efficiency comparable to record high silicon solar cell, its stability under illumination is critical problem in commercializing the photovoltaic device. Recently, charges along grain boundary was reported to be the cause of degradation of perovskite film. This article explains how perovskite lattice structure and fabrication process. It is followed by the notion that a large degree of freedom when generated arises from its defect tolerance structure property. To study how defects are dispersed on surface, electrical Force Microscopy (EFM) which is embed in atomic force microscopy was employed. EFM can effectively extract electrical signal from topography signal which enables study of charge and polarization on the surface of Hybrid metal and organic halide perovskite (HHP). Polarization domain was observed under external bias and charges redistributed along polarization domain when bias was changed properly. In addition, surface potential was in-situ scanned continuously so that we can unravel degradation mechanism. In particular, polarization domain was spotted either under bias or light and gave pictures of degrading MaPbI3.
