Air-stable and oriented mixed lead halide perovskite (FA/MA) by one-step deposition method using zinc iodide and chloroamine additive
We present a one-step method to produce air-stable, large grain mixed cationic lead perovskite films and powders under ambient condition. The introduction of 2.5 wt% of Zn(II), confirmed by X-Ray Diffraction (XRD), results in stable thin films which show the same absorption and crystal structure after two weeks of storage under ambient conditions. Next to prolonged stability, the introduction of Zn(II) affects photo-physical properties reducing the bulk defect density, enhancing the photoluminescence and extending the charge carrier lifetime. Furthermore, 3-chloropropylamine hydrochloride (3-CPACl) is applied as film-forming agent. The presence of this amine hydrochloride additive results in highly oriented and large crystal domains showing an ulterior improvement of photoluminescence intensity and lifetime. The material can also be prepared as a black precursor powder by a solid-solid reaction under ambient conditions and can be pressed into a perovskite pellet. The prolonged stability and the easy fabrication in air makes this material suitable for large scale, low cost processing for optoelectronic applications.