Optimization of CH3NH3PbI3 perovskite solar cells: A theoretical and experimental study

•Development of CH3NH3PbI3 perovskite solar cell.•Thickness optimization of spiro-OMeTAD and perovskite layers.•Study of the effect of defect density on solar cell performance.•Emphasis on the role of work function in back contact. In this work, an experimental and theoretical study on CH3NH3PbI3 perovskite solar cells was performed. A theoretical validation of experimental results in perovskite solar cells with efficiencies of 13.32% is presented. An optimization study which involves the spiro-OMeTAD and perovskite thickness’ influence on electrical output parameters (Voc, Jsc, FF and PCE) showed a promotion of solar cell efficiency to 15.50% under 100 nm and 400 nm for hole transport material and absorber, respectively. The importance of the diffusion length of the absorber is discussed. In order to enhance the efficiency, a study of defect density (NT) was applied at the range of 1016 cm−3 (experimental) to 1010 cm−3 (theoretical) where we achieved an efficiency of 20.26%. The present work illustrates the importance of thickness optimization and the reduction of defect density (by the improvement of the quality of processed film) to obtain a better performance of this type of solar cell. Furthermore, the relevance of the implementation of a back contact with higher work function was studied.