Highly (100)-oriented CH 3 NH 3 PbI 3 (Cl) perovskite solar cells prepared with NH 4 Cl using an air blow method.

The effects of adding NH 4 Cl via an air blow process on CH 3 NH 3 PbI 3 (Cl) perovskite solar cells were investigated. CH 3 NH 3 PbI 3 (Cl) solar cells containing various amounts of NH 4 Cl were fabricated by spin-coating. The microstructures of the resulting cells were investigated by X-ray diffraction, optical microscopy, and scanning electron microscopy. The current density-voltage characteristics of the cell were improved by adding an appropriate amount of NH 4 Cl and air blowing, which increased the photoconversion efficiency to 14%. Microstructure analysis indicated that the perovskite layer contained dense grains with strong (100) orientation, as a result of NH 4 Cl addition and air blowing. The ratio of the (100)/(210) reflection intensities for the perovskite crystals was 2000 times higher than that of randomly oriented grains. The devices were stable when stored in ambient air for two weeks.