Inverted planar structure of perovskite solar cells

Recently, another emerging structure, referred to as an “inverted” planar device structure (i.e., p-i-n), uses p-type and n-type materials as bottom and top charge transport layers, respectively. This structure derived from organic solar cells, and the charge transport layers used in organic photovoltaics were successfully transferred into perovskite solar cells. The p-i-n structure of perovskite solar cells have shown efficiencies as high as 18 %, lower temperature processing, flexibility, and furthermore, negligible J-V hysteresis effects. In this chapter, we will provide a comprehensive comparison of the mesoporous and planar structures, and also the regular and inverted of planar structures. Later, we will focus the discussion on the development of the inverted planar structure of perovskite solar cells, including film growth, band alignment, stability, and hysteresis. Future development and possible solutions to the remaining challenges facing the commercialization of perovskite solar cells are discussed.