Imperial College London
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Dr Robert Hoye, FIMMM CEng CSci

Faculty of Engineering, Department of Materials

Honorary Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 6048r.hoye Website

 
 
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Location

 

2.27Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Senanayak:2021:10.1002/adfm.202104981,
author = {Senanayak, S and Dai, L and Kusch, G and Shivanna, R and Zhang, Y and Pradhan, D and Ye, J and Huang, Y-T and Sirringhaus, H and Oliver, R and Greenham, N and Friend, R and Hoye, R},
doi = {10.1002/adfm.202104981},
journal = {Advanced Functional Materials},
pages = {1--9},
title = {Understanding the role of grain boundaries on charge-carrier and ion transport in Cs2AgBiBr6 thin films},
url = {http://dx.doi.org/10.1002/adfm.202104981},
volume = {31},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Halide double perovskites have gained significant attention, owing to their composition of low-toxicity elements, stability in air, and recent demonstrations of long charge-carrier lifetimes that can exceed 1 s. In particular, Cs2AgBiBr6 has been the subject of many investigations in photovoltaic devices. However, the efficiencies of solar cells based on this double perovskite are still far from the theoretical efficiency limit of the material. Here, we investigate the role of grain size on the optoelectronic properties of Cs2AgBiBr6 thin films. We show through cathodoluminescence measurements that grain boundaries are the dominant non-radiative recombination sites. We also demonstrate through field-effect transistor and temperature-dependent transient current measurements that grain boundaries act as the main channels for ion transport. Interestingly, we find a positive correlation between carrier mobility and temperature, which resembles the hopping mechanism often seen in organic semiconductors. These findings explain the discrepancy between the long diffusion lengths >1 m found in Cs2AgBiBr6 single crystals versus the limited performance achieved in their thin film counterparts. Our work shows that mitigating the impact of grain boundaries will be critical for these double perovskite thin films to reach the performance achievable based on their intrinsic single-crystal properties.
AU  - Senanayak,S
AU  - Dai,L
AU  - Kusch,G
AU  - Shivanna,R
AU  - Zhang,Y
AU  - Pradhan,D
AU  - Ye,J
AU  - Huang,Y-T
AU  - Sirringhaus,H
AU  - Oliver,R
AU  - Greenham,N
AU  - Friend,R
AU  - Hoye,R
DO  - 10.1002/adfm.202104981
EP  - 9
PY  - 2021///
SN  - 1616-301X
SP  - 1
TI  - Understanding the role of grain boundaries on charge-carrier and ion transport in Cs2AgBiBr6 thin films
T2  - Advanced Functional Materials
UR  - http://dx.doi.org/10.1002/adfm.202104981
UR  - https://onlinelibrary.wiley.com/doi/10.1002/adfm.202104981
UR  - http://hdl.handle.net/10044/1/91116
VL  - 31
ER  -
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