Mechanisms and fabrications of high efficiency organic-inorganic hybrid perovskite solar cells

Organic-inorganic hybrid perovskites have been demonstrated as excellent light absorbers for high-efficiency photovoltaic applications. The power conversion efficiency of perovskite solar cells increases dramatically from 3.8 % to a certified 22.1 % in about five years of development. The dissertation reports the research efforts of two directions: to fabricate low-cost high-efficiency perovskite solar cells and to understand the device physics behind some unusual phenomenon in perovskite solar cells. The research activities mainly focused on: 1) Understanding the basic optoelectric properties of hybrid perovskites; 2) Increasing the open-circuit voltage of perovskite solar cells by reducing the energy disorder of the electron transport layer; 3) Reducing the fabrication cost of perovskite solar cells by developing a vacuum-free low temperature lamination technique for the top electrode. 4) Elucidating the origin of photocurrent hysteresis and eliminating it by passivating the surface trap of perovskites. 5) Understanding the impact of ion migration in perovskite optoelectronics including photovoltaics and synaptic devices.