Effects of NH₄Cl addition to perovskite CH₃NH₃PbI₃ photovoltaic devices

Abstract

Effects of NH₄Cl addition to perovskite CH₃NH₃PbI₃ precursor solutions on photovoltaic properties were investigated. TiO₂/CH₃NH₃PbI₃(Cl)-based photovoltaic devices were fabricated by a spin-coating technique, and the microstructures of the devices were investigated by X-ray diffraction and scanning electron microscopy. Current density–voltage characteristics were improved by a small amount of Cl-doping, which resulted in improvement of the efficiencies of the devices. The structure analysis indicated formation of a homogeneous microstructure by NH₄Cl addition to the perovskite phase, and formation of PbI₂ was suppressed by the NH₄Cl addition.