Hybrid CdSe/CsPbI3 quantum dots for interface engineering in perovskite solar cells

Abstract

Hybrid CdSe/CsPbI₃ quantum dots (QDs) are selected for incorporation between the perovskite film and the hole transport layer (HTL). Owing to the high absorption coefficient and the suitable band gap of CsPbI₃, an optimized energy level structure can be expected. Besides, energy transfer could be realized due to the overlap between the emission spectrum of CdSe QDs and the excitation spectrum of CsPbI₃ QDs. Hence, CdSe/CsPbI₃ QDs can serve as an interface layer to promote interfacial charge extraction and enhance light harvesting ability simultaneously. Compared with pristine perovskite solar cells (PSCs), hybrid CdSe/CsPbI₃ QD incorporated PSCs achieve 21% enhancement in power conversion efficiency (PCE). The enhancement of PCE can be ascribed to the ultrafast charge carrier dynamics and Förster resonance energy transfer (FRET) effect. The design of hybrid CdSe/CsPbI₃ QDs offers an alternative method for interfacial engineering to enhance optical properties and facilitate the charge transport process in PSCs.