Correlation Between the Preparation Methods and the Structural Morphologies of Organometallic Halide Perovskite Thin Films

Organometallic halide perovskites are emerging as a promising class of materials for optoelectronic and electrical applications. The degree of molecular ordering that depends on nucleation and growth processes can tune their morphological structure which in turn affects the resultant optical, electronic and electrical properties. Studies have been carried out in this area of research, to some degree, but not conclusive. A systematic study on how the preparation method determines the various morphologies of the resultant perovskite thin films is thus necessary. This work presents a study that was carried out to assess the relationship between different deposition methods and the resulting morphologies of organometallic halide perovskite thin films. In this study, single step solution deposition method, two step solution deposition method and two step drop casting solution deposition methods were used to prepare the perovskite thin films. Concentration, annealing temperature, blade coating speed and dipping times were varied during perovskite deposition processes and the optical micrographs of the prepared films obtained using Zeiss Axio 100 optical microscope fitted with AxioCam 105 color camera. Significant difference in morphologies of the structures prepared using different deposition methods was observed. This observable difference in morphologies may be related to the molecular order of the film structures