Influence of end groups variation of self assembled monolayers on performance of planar perovskite solar cells by interface regulation

Abstract

We present the synthesis and application of new class of self-assembled monolayer molecules (SAMs) for acquiring feasible interfacial engineering in inverted type perovskite solar cells (PSCs). The proposed SAMs bearing different electron donating terminal groups have been utilized to tune the work function of indium tin oxide (ITO) electrodes. Fine-tuning of terminal groups of the SAMs allows us to compare relationship between molecular structures and device parameters. Moreover, ionic and hybrid nature of perovskite enables forming various chemical interactions with terminal groups of SAMs. Employed SAMs has resulted in permanent increase in work function of ITO, increase power conversion efficiency (PCE) of the cells and passivation of trap states at the interface between electrode and perovskite layer. The present study provides new insights into correlation between molecular engineering and solar cell performance through treating holistic comparison of synthesized molecules at the interface of ITO and perovskite layer.