Substrate-dependent Growth of CH3NH3PbI3Films Deposited by Vacuum Evaporation

Abstract

CH3NH3PbI3 (MAPbI3) films were prepared by dual-source vacuum evaporation on Au, poly(3,4-ethylenedioxythiophene) (PEDOT), and indium-tin-oxide(ITO) with the similar deposition parameters. The films were characterized with X-ray diffraction (XRD), steady-state photoluminescence (PL) and Raman spectroscopy. The interface electronic structures of co-evaporated MAPbI3 films on different substrates were studied with ultraviolet photoemission spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS). The research indicates that Au is more suitable for the film growth than the other substrates, especially when the film is very thin. The poor adsorption of the precursors may make it difficult to form MAPbI3 thin film on ITO. Furthermore, it is found that the charge transfer efficiency at the interface between PEDOT and MAPbI3 is relatively high, which indicates that PEDOT can act as an effective hole transport layer for MAPbI3-based devices.