yznoC_revised2.pdf (2.91 MB)
Yttrium doped ZnO nanorod arrays for increased charge mobility and carrier density for enhanced solar water splitting
journal contribution
posted on 2023-06-09, 18:25 authored by Daniel Holt, Grant Brown, Peter Mcnulty, Christopher Dadswell, John SpencerJohn Spencer, Qiao ChenQiao ChenAn innovative procedure is presented, when for the first time, yttrium doped ZnO vertically aligned nanorods have been synthesized using a unique rapid microwave assisted method. In comparison with pristine ZnO NRs, the Y-doped samples present more favourable morphology along with reduced crystallinity due to substitutional defects, YZn. The Y acted as a shallow donor type defect, leading to an 80% increase in dopant density, to 1.36×1018 cm-2 in the 0.15% Y sample. The transmission line model was used to analyse the transport properties. It was found that a 1000-fold increase in conductivity and electron mobility was achieved by doping 0.15% Y, resulting in a high density of donors which fill charge traps. Meanwhile, a significant improvement in conductivity was accompanied by greater electron hole recombination and band gap reduction. Analysis of photoluminescence spectra reveals the effect of Y doping on native point defects, initially reducing Zn2+ vacancies by filling with YZn, followed by the reduction of O2- vacancies with interstitial doping at higher Y concentration. With a fine balance of superior conductivity and charge recombination rate, the photocatalytic water splitting performance was optimised achieving photocurrent of 0.84 mA cm-2 at 1.23 VRHE with 0.1% Y doping. This corresponded to a 47% enhancement in photoconversion efficiency compared to the pristine sample.
History
Publication status
- Published
File Version
- Accepted version
Journal
The Journal of Physical Chemistry CISSN
1932-7455Publisher
American Chemical SocietyExternal DOI
Department affiliated with
- Chemistry Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2019-07-17First Open Access (FOA) Date
2020-07-11First Compliant Deposit (FCD) Date
2019-07-16Usage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC