Improving the Efficiency and Reproducibility of Organic-inorganic Halide Perovskite Solar Cell

Abstract

Organic-inorganic halide perovskites have garnered a lot of attention in the field of photovoltaic materials research. This novel PV material possesses a combination of remarkable optoelectronic properties, such as steep optical absorption edge and high absorption coefficients, long charge carrier diffusion lengths and lifetimes. Solution processability, cheap starting materials, and striking optoelectronic properties have these materials a cheaper alternative to the quite expensive widely used polycrystalline silicon for photovoltaic applications. The focus of this study is on improving efficiency of the inverted planar organicinorganic halide perovskites based solar cell with glass/ITO/PEDOT:PSS/Perovskite/PCBM/TiOx/Al layers stack. To improve efficiency, a layer by layer approach of optimization was adopted and the effects of each step were also compared as the perovskite synthesis route was varied. Results show that while room temperature methylamine gas treatment improved the crystallinity of MAPI (CH3NH3PbI3- xClx) perovskite, it converts CsMAFA (Cs5(FA0.83MA0.17)95Pb(I0.83Br0.17)3) perovskite to its non-photovoltaic yellow polymorph. We found improved crystal growth for the CsMAFA perovskite is best achieved via DMF solvent vapor annealing. Through PEDOT:PSS and PCBM layers optimization, a maximum PCE of 2.11% and 13.49% were achieved for MAPI and CsMAFA perovskites solar cells respectively.