Ultra‐Thin SnOx Buffer Layer Enables High‐Efficiency Quantum Junction Photovoltaics. Issue 36 (26th October 2022)

• Record Type: Journal Article
• Authors: Jia, Yuwen; Wang, Haibin; Wang, Yinglin; Wang, Chao; Li, Xiaofei; Kubo, Takaya; Liu, Yichun; Zhang, Xintong; Segawa, Hiroshi
• Is Part Of: Advanced science. Volume 9:Issue 36(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-26
• Subjects: capacitance effect -- hysteresis -- interfacial modification -- quantum junction solar cells; Science -- Periodicals; 505
• DOI: 10.1002/advs.202204725
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Solution‐processed solar cells are promising for the cost‐effective, high‐throughput production of photovoltaic devices. Colloidal quantum dots (CQDs) are attractive candidate materials for efficient, solution‐processed solar cells, potentially realizing the broad‐spectrum light utilization and multi‐exciton generation effect for the future efficiency breakthrough of solar cells. The emerging quantum junction solar cells (QJSCs), constructed by n‐ and p‐type CQDs only, open novel avenue for all‐quantum‐dot photovoltaics with a simplified device configuration and convenient processing technology. However, the development of high‐efficiency QJSCs still faces the challenge of back carrier diffusion induced by the huge carrier density drop at the interface of CQDs and conductive glass substrate. Herein, an ultra‐thin atomic layer deposited tin oxide (SnOx ) layer is employed to buffer this carrier density drop, significantly reducing the interfacial recombination and capacitance caused by the back carrier diffusion. The SnOx ‐modified QJSC achieves a record‐high efficiency of 11.55% and a suppressed hysteresis factor of 0.04 in contrast with reference QJSC with an efficiency of 10.4% and hysteresis factor of 0.48. This work clarifies the critical effect of interfacial issues on the carrier recombination and hysteresis of QJSCs, and provides an effective pathway to design high‐performance all‐quantum‐dot devices. Abstract : This work, for the first time introduces an ALD‐deposited ultrathin SnOx buffer layer to further improve the performance of QJSCs. The authors in‐depth investigated the significant influence of interfacial carrier density difference on the J − V hysteresis of QJSCs and almost eliminated this hysteresis by the SnOx buffer layer. This work paves an effective pathway to the development of high‐performance all‐quantum‐dot photovoltaic devices.