Lithium Fluoride Nanolayer Modification of Substrates Upgrading the Performance of Perovskite Solar Cells

Résumé fourni par la source

Abstract Perovskite solar cells (PSCs) have become a research hotspot in the photovoltaic field, while the fluorine-doped tin oxide substrate/electron transport layer (FTO/ETL) interface is a blind spot in PSC research. Hence, a nanolayer of alkali metal fluoride (MF: LiF, NaF, KF) is inserted into the interlayer between FTO and SnO2 ETL. In the subsequent annealing, F– anions are firmly adsorbed on the surface of the FTO anode, while some M+ cations diffuse into the SnO2 and perovskite to form a like-diffuse electric double layer (L-DEDL) and a built-in dipole field at the FTO/ETL interface. The L-DEDL optimizes the energy level alignment and suppresses the reverse migration of ions. Compared to K and Na, Li has a smaller ionic radius and a smaller electronegativity difference with F element, thus Li is more prone to diffuse and produce more significant modulation effects. Therefore, the LiF-modified device achieved a power conversion efficiency (PCE) of 26.13% along with improved stability, while the pristine device had a PCE of only 23.07%.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.