Properties of atmospheric‑hydrogen-plasma-treated CH3NH3PbI3 perovskite films

Caused by unique properties of organic-inorganic hybrid perovskite films, the patterning process is very challenging. In this study, novel method for etching of perovskite film is suggested using atmospherically hydrogen-containing plasma treatment. It is illustrated successful eating of methylammonium triiodideplumbate (CH3NH3PbI3) perovskite films on glass substrates. Perovskite layers are processed for various times between 2 s and 300 s. Based on the transformation of film's morphology upon treatment time three regions are distinguished; i.e. short (less than 10s), medium (up to 180 s) and long (> 180 s). Although onset of the early modifications is observed after 10 s treatment the bulk characteristics of the film remain mainly the same. After 30 s treatment nano-sized particles are observed in the entire film. When plasma treatment performed longer period i.e. 180 and 300 s, some particles are agglomerated forming relatively large clusters. The morphological and chemical properties of the plasma-processed films are analyzed using various analytical tools such as scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy coupled with SEM or TEM (EDS-SEM and EDS-TEM), and x-ray photoelectron spectroscopy (XPS).