Imperial College London
Alternate

DrPiersBarnes

Faculty of Natural Sciences, Department of Physics

Lecturer in Experimental Solid State Physics
 
 
 
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Contact

 

+44 (0)20 7594 7609piers.barnes

 
 
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Location

 

1003Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Du:2018:10.1002/adfm.201801808,
author = {Du, T and Kim, J and Ngiam, J and Xu, S and Barnes, P and Durrant, J and McLachlan, MA},
doi = {10.1002/adfm.201801808},
journal = {Advanced Functional Materials},
title = {Elucidating the origins of sub-gap tail states and open-circuit voltage in methylammonium lead triiodide perovskite solar cells},
url = {http://dx.doi.org/10.1002/adfm.201801808},
volume = {28},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Recombination via sub-gap trap states is considered a limiting factor in the development of organometal halide perovskite solar cells. Here, we demonstrate the impact of active layer crystallinity on the accumulated charge and open-circuit voltage (Voc) in solar cells based on methylammonium lead triiodide (CH3NH3PbI3, MAPI). We show MAPI crystallinity can be systematically tailored by modulating the stoichiometry of the precursor mix, where small quantities of excess methylammonium iodide (MAI) improves crystallinity increasing device Voc  by ~200 mV. Using in-situ differential charging and transient photovoltage measurements, charge density and charge carrier recombination lifetime are determined under operational conditions. Increased Voc is correlated to improved active layer crystallinity and a reduction in the density of trap states in MAPI. Photoluminescence spectroscopy shows that an increase in trap states correlates with faster carrier trapping and more non-radiative recombination pathways. We provide fundamental insights into the origin of Voc in perovskite photovoltaics and demonstrate why highly crystalline perovskite films are paramount for high-performance devices.
AU  - Du,T
AU  - Kim,J
AU  - Ngiam,J
AU  - Xu,S
AU  - Barnes,P
AU  - Durrant,J
AU  - McLachlan,MA
DO  - 10.1002/adfm.201801808
PY  - 2018///
SN  - 1616-301X
TI  - Elucidating the origins of sub-gap tail states and open-circuit voltage in methylammonium lead triiodide perovskite solar cells
T2  - Advanced Functional Materials
UR  - http://dx.doi.org/10.1002/adfm.201801808
UR  - http://hdl.handle.net/10044/1/59924
VL  - 28
ER  -
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