Hot airflow deposition: Toward high quality MAPbI3 perovskite films

This work aims to investigate the effect of the hot airflow, during the growth of MAPbI(3) films using the spin-coating process, on the structural, optical and morphological properties of the films. The experimental results show that many physical properties of the perovskite strongly depend on the airflow temperature which has a beneficial effect on the perovskite quality. This process enabled complete surface coverage and a clear improvement of the crystallinity and the crystallite size of the MAPbI(3) perovskite. In fact, SEM micrographs show that significant homogenous nucleation, uniform surface distribution, pin holes free and a highest surface coverture of 98% are achieved when the airflow temperature reaches 100 degrees C. At this temperature, the optical absorbance of the films are also improved. Furthermore, the PL analyses performed on the films heated using the airflow at 100 degrees C show fewer non-radiative defects and confirm the crystallinity improvement. However, a remarkable degradation of the MAPbI(3) perovskites associated to the PbI2 phase formation is noticed when the hot airflow temperature is higher than 100 degrees C, especially 300 degrees C. (C) 2019 Elsevier B.V. All rights reserved.