Crystal growth engineering for high efficiency perovskite solar cells

The perovskite solar cell is based on organicinorganic lead halides such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)(2)PbI3 as light harvesters. Since the first report on a longterm, durable, 9.7% efficient solidstate perovskite solar cell in 2012, the perovskite solar cell has received great attention because of facile processing and superb photovoltaic performance. As a result, a power conversion efficiency exceeding 22% was certified in 2016. To achieve a high efficiency perovskite solar cell, understanding the crystal structure and optoelectronic properties of organicinorganic lead halide perovskites are of importance. Growth of perovskite on substrate without traps and grain boundaries is equally important for attaining high efficiency. In this article, the emergence of the perovskite solar cell, the structural and optoelectronic characteristics of perovskite materials and the methodologies of perovskite crystal growth both from solution and on a substrate are reviewed.