Efficiency and Stability Enhancement in Perovskite Solar Cells by Inserting Lithium‐Neutralized Graphene Oxide as Electron Transporting Layer

Abstract

This work proposes a new perovskite solar cell structure by including lithium‐neutralized graphene oxide (GO‐Li) as the electron transporting layer (ETL) on top of the mesoporous TiO 2 (m‐TiO 2 ) substrate. The modified work‐function of GO after the intercalation of Li atoms (4.3 eV) exhibits a good energy matching with the TiO 2 conduction band, leading to a significant enhancement of the electron injection from the perovskite to the m‐TiO 2 . The resulting devices exhibit an improved short circuit current and fill factor and a reduced hysteresis. Furthermore, the GO‐Li ETL partially passivates the oxygen vacancies/defects of m‐TiO 2 by resulting in an enhanced stability under prolonged 1 SUN irradiation.