Optical Switching of Hole Transfer in Double-Perovskite/Graphene Heterostructure

Optical Switching of Hole Transfer in Double-Perovskite/Graphene Heterostructure

© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 35(2023), 29 vom: 15. Juli, Seite e2211198
1. Verfasser: Zhang, Heng (VerfasserIn)
Weitere Verfasser: Debroye, Elke, Fu, Shuai, González, Miriam C Rodriguez, du Fossé, Indy, Geuchies, Jaco J, Gao, Lei, Yu, Xiaoqing, Houtepen, Arjan J, De Feyter, Steven, Hofkens, Johan, Bonn, Mischa, Wang, Hai I
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2023
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article charge transfer double perovskites graphene terahertz spectroscopy
Beschreibung
Zusammenfassung:© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.
Synergically combining their respective ultrahigh charge mobility and strong light absorption, graphene (Gr)/semiconductor heterostructures are promising building blocks for efficient optoelectronics, particularly photodetectors. Charge transfer (CT) across the heterostructure interface crucially determines device efficiency and functionality. Here, it is reported that hole-transfer processes dominate the ultrafast CT across strongly coupled double-perovskite Cs2 AgBiBr6 /graphene (DP/Gr) heterostructures following optical excitation. While holes are the primary charges flowing across interfaces, their transfer direction, as well as efficiency, show a remarkable dependence on the excitation wavelength. For excitation with photon energies below the bandgap of DPs, the photoexcited hot holes in Gr can compete with the thermalization process and inject into in-gap defect states in DPs. In contrast, above-bandgap excitation of DP reverses the hole-transfer direction, leading to hole transfer from the valence band of DPs to Gr. Experimental evidence that increasing the excitation photon energy enhances CT efficiency for both below- and above-bandgap photoexcitation regimes is further provided, unveiling the positive role of excess energy in enhancing interfacial CT. The possibility of switching the hole-transfer direction and thus the interfacial photogating field by tuning the excitation wavelength, provides a novel way to control the interfacial charge flow across a DP/Gr heterojunction
Beschreibung:Date Revised 20.07.2023
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.202211198