Low temperature TiOx compact layer by chemical bath deposition method for vapor deposited perovskite solar cells

In this paper, we try to fabricate the planer heterojunction (PHJ) perovskite solar cell based on low temperature TiOx compact layer by chemical bath deposition (CBD) method. We compared solar cell properties between compact-TiO _x layer and compact-TiO ₂ layer, where CBD deposited films were heated at 250 °C in order to convert into TiO _x amorphous state and 450 °C intoTiO ₂ anatase state, respectively. Power conversion efficiency of PHJ perovskite solar cell based on our compact-TiO _x shows almost same as that of TiO ₂ one. In addition, we discuss the origin of hysteresis of PHJ perovskite solar cell based on compact-TiO _x and TiO ₂ . We conclude that hysteresis of PHJ perovskite solar cell is heavily influenced by surface coverage and roughness of compact-TiO _x or TiO ₂ layers on transparent conducting oxide.