TY - JOUR

T1 - Unveiling Charge Carrier Dynamics at Organic–Inorganic S-Scheme Heterojunction Interfaces: Insights From Advanced EPR

AU - Gu, Miaoli

AU - Zhang, Jianjun

AU - Kurganskii, Ivan V.

AU - Poryvaev, Artem S.

AU - Fedin, Matvey V.

AU - Cheng, Bei

AU - Yu, Jiaguo

AU - Zhang, Liuyang

N1 - The authors thank Mr. Dmitry Syrtsov (ITC SB RAS) for performing some CW EPR measurements. This work was supported by a joint project, the Russian Science Foundation (24-201043-201000045) and the National Natural Science Foundation of China (22361132529). The authors also acknowledge the National Natural Science Foundation of China (52322214, 22238009, 52073223, 22278324, and 22361142704); the National Science Foundation of Hubei Province of China (2022CFA001 and 2023AFA088).

PY - 2024

Y1 - 2024

N2 - Understanding charge carrier transfer at heterojunction interfaces is critical for advancing solar energy conversion technologies. This study utilizes continuous wave (CW), pulse, and time-resolved (TR) electron paramagnetic resonance (EPR) spectroscopy to explore the radical species formed at the TAPA (tris(4−aminophenyl)amine)-PDA (Terephthaldicarboxaldehyde)/ZnIn2S4 (TP/ZIS) heterojunction interface. CW and pulse EPR identify stable radical defects localized near the interface, accessible to water molecules. Time-resolved EPR reveals a photoinduced electron transfer from TP to ZIS, leading to the generation of spin-correlated radical pairs under light irradiation, signifying efficient charge carrier separation and spatial transfer within the S-scheme heterojunction. This electron transfer mechanism, confirmed through in situ X–ray photoelectron spectroscopy and femtosecond transient absorption spectroscopy, suppresses undesirable carrier recombination, extending charge carrier lifetimes. These findings provide novel insights into the transport direction of charge carriers at the S-scheme heterojunction interface, offering valuable guidance for designing highly efficient and stable organic–inorganic heterojunction photocatalysts for solar energy applications.

AB - Understanding charge carrier transfer at heterojunction interfaces is critical for advancing solar energy conversion technologies. This study utilizes continuous wave (CW), pulse, and time-resolved (TR) electron paramagnetic resonance (EPR) spectroscopy to explore the radical species formed at the TAPA (tris(4−aminophenyl)amine)-PDA (Terephthaldicarboxaldehyde)/ZnIn2S4 (TP/ZIS) heterojunction interface. CW and pulse EPR identify stable radical defects localized near the interface, accessible to water molecules. Time-resolved EPR reveals a photoinduced electron transfer from TP to ZIS, leading to the generation of spin-correlated radical pairs under light irradiation, signifying efficient charge carrier separation and spatial transfer within the S-scheme heterojunction. This electron transfer mechanism, confirmed through in situ X–ray photoelectron spectroscopy and femtosecond transient absorption spectroscopy, suppresses undesirable carrier recombination, extending charge carrier lifetimes. These findings provide novel insights into the transport direction of charge carriers at the S-scheme heterojunction interface, offering valuable guidance for designing highly efficient and stable organic–inorganic heterojunction photocatalysts for solar energy applications.

KW - EPR

KW - S-scheme heterojunction

KW - extended carrier lifetime

KW - interfacial charge transfer

KW - organic–inorganic

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85212063462&origin=inward&txGid=8fa73b84de3e66c4722f56a4c7c6c628

UR - https://www.mendeley.com/catalogue/aa955c58-086d-300c-88e2-0e5582e388f7/

U2 - 10.1002/adma.202414803

DO - 10.1002/adma.202414803

M3 - Article

C2 - 39676493

JO - Advanced Materials

JF - Advanced Materials

SN - 0935-9648

ER -