Recent progress in organic-inorganic halide perovskite solar cells : mechanisms and material design

While energy shortage is always an issue, the impending exhaustion of fossil fuel sources makes it an ever increasingly pressing one. Photovoltaic technology brings hope in the struggle to alleviate this problem, but no solar cell has yet fulfilled the requirements of the viability of large scale production together with high efficiency and low cost. Fortunately, recently reported organic-inorganic halide perovskites, possessing the desirable properties of a high absorption coefficient, a long charge diffusion length, an appropriate band gap, and solution processability, show great potential for photovoltaic applications. Within a few years, the power conversion efficiency of perovskite solar cells has increased from 3.8% to 19.3%. Reports on new preparation methods and materials continue to emerge. While reviews have focused on mechanisms, cell structures, preparation methods and materials applied, it is important to give a combined overview of all these aspects. Furthermore, this review considers the newly reported preparation methods and mechanisms and summarizes the applied materials for each function of these solar cells.