Abstract

A simple dual-quartz crystal microbalance (QCM) method was developed to controllably evaporate highly volatile CH3NH3I (MAI) by thermal vapor deposition for the fabrication of halide perovskite (HaP) photovoltaic (PV) devices. Dual vapor stream boat sources were used, allowing a fine-tunning of the applied power, temperature, and, therefore, the co-deposition rate of MAI and PbI2. X-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy confirmed that the composition of the films remained constant throughout the deposition of the precursors on multiple substrates. Current-voltage curves and external quantum efficiency measurements demonstrated the method's reproducibility, offering a simple alternative to obtain vacuum-processed HaP for PV and other optoelectronic applications.