Imperial College London
Portrait Picture

DrAndreasKafizas

Faculty of Natural Sciences, Department of Chemistry

Senior Lecturer
 
 
 
//

Contact

 

+44 (0)20 7594 6752a.kafizas Website

 
 
//

Location

 

301GMolecular Sciences Research HubWhite City Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Corby:2019:10.1021/acs.jpclett.9b01935,
author = {Corby, S and Pastor, E and Dong, Y and Zheng, X and Francàs, L and Sachs, M and Selim, S and Kafizas, A and Bakulin, AA and Durrant, JR},
doi = {10.1021/acs.jpclett.9b01935},
journal = {Journal of Physical Chemistry Letters},
pages = {5395--5401},
title = {Charge separation, band-bending, and recombination in WO3 photoanodes},
url = {http://dx.doi.org/10.1021/acs.jpclett.9b01935},
volume = {10},
year = {2019}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - In metal oxide-based photoelectrochemical devices, the spatial separation of photogenerated electrons and holes is typically attributed to band-bending at the oxide/electrolyte interface. However, direct evidence of such band-bending impacting upon charge carrier lifetimes has been very limited to date. Herein we use ultrafast spectroscopy to track the rapid relaxation of holes in the space-charge layer and their recombination with trapped electrons in WO3 photoanodes. We observe that applied bias can significantly increase carrier lifetimes on all time scales from picoseconds to seconds and attribute this to enhanced band-bending correlated with changes in oxygen vacancy state occupancy. We show that analogous enhancements in carrier lifetimes can be obtained by changes in electrolyte composition, even in the absence of applied bias, highlighting routes to improve photoconversion yields/performance, through changes in band-bending. This study thus demonstrates the direct connection between carrier lifetime enhancement, increased band-bending, and oxygen vacancy defect state occupancy.
AU  - Corby,S
AU  - Pastor,E
AU  - Dong,Y
AU  - Zheng,X
AU  - Francàs,L
AU  - Sachs,M
AU  - Selim,S
AU  - Kafizas,A
AU  - Bakulin,AA
AU  - Durrant,JR
DO  - 10.1021/acs.jpclett.9b01935
EP  - 5401
PY  - 2019///
SN  - 1948-7185
SP  - 5395
TI  - Charge separation, band-bending, and recombination in WO3 photoanodes
T2  - Journal of Physical Chemistry Letters
UR  - http://dx.doi.org/10.1021/acs.jpclett.9b01935
UR  - https://www.ncbi.nlm.nih.gov/pubmed/31416313
UR  - http://hdl.handle.net/10044/1/74063
VL  - 10
ER  -
Download