Thiazole‐Modified C3N4 Interfacial Layer for Defect Passivation and Charge Transport Promotion in Perovskite Solar Cells. Issue 3 (15th January 2021)

• Record Type: Journal Article
• Authors: Wang, Lian; Fu, Lin; Li, Bo; Li, Hui; Pan, Lu; Chang, Bohong; Yin, Longwei
• Is Part Of: Solar RRL. Volume 5:Issue 3(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-01-15
• Subjects: C3N4 -- charge transport -- defect passivation -- interfaces -- perovskite solar cells; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202000720
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : Despite the conspicuous achievements in perovskite solar cells (PSCs), further improvement of the power conversion efficiency (PCE) is hindered by substantially detrimental carrier recombination resulting from the high interfacial charge defect density and inferior charge transport kinetics. Herein, an interface engineering strategy is developed to introduce a Lewis base thiophene or thiazole–modified C3 N4 layer at the electron transfer layer (ETL)/perovskite interface to constitute a stepwise energy band alignment and passivate defects at interfaces of the perovskite film. Attributed to its well‐matched energy level with TiO2 and perovskite, the charge extraction efficiency and charge transfer dynamics can be promoted remarkably, greatly inhibiting charge recombination at the interface. Furthermore, thiophene and thiazole can donate the lone pair electrons in S or N atoms to undercoordinated Pb 2+, which effectively passivates the electronic trap states caused by halogen vacancies, thereby greatly minimizing trap‐assisted nonradiative recombination in the PSCs. Eventually, the thiazole–C3 N4 /perovskite‐based devices acquire an outstanding efficiency of 19.23%, supported by an enhanced open‐circuit voltage ( V OC ) of 1.11 V with improved moisture stability. This work provides an avenue for interfacial energy level modulation and defect passivation strategies for a rational interface microstructure design for meliorating the performance of PSCs. Abstract : A C3 N4 layer functionalized with thiazole is introduced to the electron transfer layer/perovskite interface, which serves as an intermediate energy level to constitute a stepwise energy band alignment and donates the lone pair electrons to undercoordinated Pb 2+ . Resultantly, it effectively passivates the interfacial defects and promotes carrier transport, thereby further boosting the efficiency of the device.