High quality perovskite thin films induced by crystal seeds with lead monoxide interfacial engineering
Interfacial engineering is an important method to achieve compact and smooth high-quality perovskite films in a one-step method. In this work, we first demonstrate that lead monoxide (PbO) as an interfacial modification material could convert to perovskite crystal seeds and induce the growth of the CH3NH3PbI3−xClx absorber layer. The introduction of the perovskite crystal seeds resulted in a dramatically enhanced coverage and a large grain size of the perovskite films. The PL lifetime measurements verified reduced trap states of the perovskite thin films and enhanced charge transfer at the TiO2/perovskite interface. With a high quality perovskite thin film, the planar perovskite solar cell showed a remarkably improved power conversion efficiency (PCE) of 17.03%. Moreover, the device with PbO as an interfacial layer exhibited superior UV-stability, maintaining 60% of the initial PCE under intensive UV irradiation for 180 min while the control device was almost exhausted.