Molecular Bridge on Buried Interface for Efficient and Stable Perovskite Solar Cells.

Abstract

The interface of perovskite solar cells (PSCs) is significantly important for charge transfer and device stability, while the buried interface with the impact on perovskite film growth has been paid less attention. Herein, we use a molecular modifier, glycocyamine (GDA) to build a molecular bridge on the buried interface of SnO2 /perovskite, resulting in superior interfacial contact. This is achieved through the strongly interaction between GDA and SnO2 , which also appreciably modulates the energy level. Moreover, GDA can regulate the perovskite crystal growth, yielding perovskite film with enlarged grain size and absence of pinholes, exhibiting substantially reduced defect density. Consequently, PSCs with GDA modification demonstrate significant improvement of open circuit voltage (close to 1.2 V) and fill factor, leading to an improved power conversion efficiency from 22.60 % to 24.70 %. Additionally, stabilities of GDA devices under maximum power point and 85 °C heat both perform better than the control devices.