Probing structure–property relationship in chemical vapor deposited hybrid perovskites by pressure and temperature

Abstract

Chemical vapor deposition (CVD), a low-cost and a scalable deposition technique, allows the growth of methylammonium lead iodide (MAPbI3) films without the use of solvents, substantially increasing air stability while also inducing the stable cubic phase at room temperature and at pressures as low as 0.25 GPa. MAPbI3 thin films were grown by a facile two-step low-pressure vapor deposition process in a single reactor. This method results in films, which are usually in the tetragonal phase (space group: I4/mcm) and occasionally in the cubic phase under ambient conditions. High-pressure synchrotron-based X-ray diffraction studies from CVD-grown MAPbI3 crystallites show that the sample remains in the cubic phase (space group: Im $$\bar{3}$$ ) between 0.25 and 3.0 GPa. Temperature-dependent transport measurements show sharp anomalies, correlating with the structural changes. The transport measurements from the CVD-grown cubic MAPI3 film is further compared with a film in the tetragonal phase.