Ibrahem MA, Verrelli E, Adawi AM, Bouillard JSG, O’Neill M. Plasmons Enhancing Sub-Bandgap Photoconductivity in TiO
2 Nanoparticles Film.
ACS OMEGA 2024;
9:10169-10176. [PMID:
38463264 PMCID:
PMC10918839 DOI:
10.1021/acsomega.3c06932]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 01/16/2024] [Accepted: 01/24/2024] [Indexed: 03/12/2024]
Abstract
The coupling between sub-bandgap defect states and surface plasmon resonances in Au nanoparticles and its effects on the photoconductivity performance of TiO2 are investigated in both the ultraviolet (UV) and visible spectrum. Incorporating a 2 nm gold nanoparticle layer in the photodetector device architecture creates additional trapping pathways, resulting in a faster current decay under UV illumination and a significant enhancement in the visible photocurrent of TiO2, with an 8-fold enhancement of the defects-related photocurrent. We show that hot electron injection (HEI) and plasmonic resonance energy transfer (PRET) jointly contribute to the observed photoconductivity enhancement. In addition to shedding light on the below-band-edge photoconductivity of TiO2, our work provides insight into new methods to probe and examine the surface defects of metal oxide semiconductors using plasmonic resonances.
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