Suppression of charge carrier recombination in a Ta3N5 photoanode via defect regulation: a theoretical investigation

Defect-induced charge carrier recombination in a photoanode significantly restricts the efficiency of solar-driven water splitting. By systematically investigating the photoexcited charge carrier recombination dynamics of Ta3N5 with intrinsic defects, charge states, oxygen (O) impurities, and metal...

Full description

Saved in:
Bibliographic Details
Published in:Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2024-07, Vol.12 (26), p.15922-15929
Main Authors: Fan, Guozheng, Zhou, Zhaobo, Yu, Jing, Frauenheim, Thomas
Format: Article
Language:English
Subjects:
Carrier lifetime
Carrier recombination
Current carriers
Defects
Density functional theory
Doping
Impurities
Magnesium
Molecular dynamics
Nitrogen
Photoanodes
Recombination
Tantalum
Tantalum nitrides
Water splitting
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Defect-induced charge carrier recombination in a photoanode significantly restricts the efficiency of solar-driven water splitting. By systematically investigating the photoexcited charge carrier recombination dynamics of Ta3N5 with intrinsic defects, charge states, oxygen (O) impurities, and metal doping based on density functional theory (DFT) calculations and nonadiabatic molecular dynamics (NAMD) simulations, we propose two strategies to mitigate defect-induced charge carrier recombination: ionizing nitrogen (N) vacancies and magnesium (Mg) doping. Our results show that tantalum (Ta) reduction induced by N vacancies is the primary factor in reducing the carrier lifetime of the Ta3N5 photoanode. Ionizing N vacancies and Mg doping can tune the charges of reduced Ta species near the N vacancies, thus extending the recombination lifetime. By contrast, charge-balanced metal and O impurities co-doping in Ta3N5 photoanodes cannot significantly increase the lifetime. Our investigation sheds new light on understanding the charge carrier recombination mechanism and provides dependable strategies to improve the water-splitting performance of the Ta3N5 photoanode.
ISSN:2050-7488
2050-7496
DOI:10.1039/d4ta01693a