Imperial College London
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ProfessorAronWalsh

Faculty of Engineering, Department of Materials

Chair in Materials Design
 
 
 
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Contact

 

+44 (0)20 7594 1178a.walsh Website

 
 
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Location

 

2.10Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Huang:2022,
author = {Huang, Y-T and Kavanagh, S and Righetto, M and Rusu, M and Levine, I and Unold, T and Zelewiski, S and Sneyd, A and Zhang, K and Dai, L and Britton, A and Ye, J and Julin, J and Napari, M and Zhang, Z and Xiao, J and Laitinen, M and Torrente-Murciano, L and Stranks, S and Rao, A and Herz, L and Scanlon, D and Walsh, A and Hoye, R},
journal = {Nature Communications},
title = {Strong absorption and ultrafast localisation in NaBiS2 nanocrystals with slow charge-carrier recombination},
url = {http://hdl.handle.net/10044/1/98641},
volume = {13},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - I-V-VI2 ternary chalcogenides are gaining attention as earth-abundant, nontoxic, and air-stable absorbers for photovoltaic applications. However, the semiconductors explored thus far have slow absorption onsets, and their charge-carrier transport is not well understood yet. Herein, we investigate cation-disordered NaBiS2 nanocrystals, which have a steep absorption onset, with absorption coefficients reaching >105 cm-1 just above its pseudo-direct bandgap of 1.4 eV. Surprisingly, we also observe an ultrafast (at picosecond-time scale) photoconductivity decay and long-lived charge-carrier population persisting for over one microsecond in NaBiS2 nanocrystals. These unusual features arise because of the localised, non-bonding S p character of the upper valence band, which leads to a high density of electronic states at the band edges, ultrafast localisation of spatially-separated electrons and holes, as well as the slow decay of trapped holes. This work reveals the critical role of cation disorder in these systems on both absorption characteristics and charge-carrier kinetics.
AU  - Huang,Y-T
AU  - Kavanagh,S
AU  - Righetto,M
AU  - Rusu,M
AU  - Levine,I
AU  - Unold,T
AU  - Zelewiski,S
AU  - Sneyd,A
AU  - Zhang,K
AU  - Dai,L
AU  - Britton,A
AU  - Ye,J
AU  - Julin,J
AU  - Napari,M
AU  - Zhang,Z
AU  - Xiao,J
AU  - Laitinen,M
AU  - Torrente-Murciano,L
AU  - Stranks,S
AU  - Rao,A
AU  - Herz,L
AU  - Scanlon,D
AU  - Walsh,A
AU  - Hoye,R
PY  - 2022///
SN  - 2041-1723
TI  - Strong absorption and ultrafast localisation in NaBiS2 nanocrystals with slow charge-carrier recombination
T2  - Nature Communications
UR  - http://hdl.handle.net/10044/1/98641
VL  - 13
ER  -
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