Imperial College London

ProfessorAronWalsh

Faculty of EngineeringDepartment of Materials

Chair in Materials Design
 
 
 
//

Contact

 

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

 
 
//

Location

 

2.10Royal School of MinesSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Doherty:2020:10.1038/s41586-020-2184-1,
author = {Doherty, TAS and Winchester, AJ and Macpherson, S and Johnstone, DN and Pareek, V and Tennyson, EM and Kosar, S and Kosasih, FU and Anaya, M and Abdi-Jalebi, M and Andaji-Garmaroudi, Z and Wong, EL and Madeo, J and Chiang, Y-H and Park, J-S and Jung, Y-K and Petoukhoff, CE and Divitini, G and Man, MKL and Ducati, C and Walsh, A and Midgley, PA and Dani, KM and Stranks, SD},
doi = {10.1038/s41586-020-2184-1},
journal = {Nature},
pages = {360--366},
title = {Performance-limiting nanoscale trap clusters at grain junctions in halide perovskites},
url = {http://dx.doi.org/10.1038/s41586-020-2184-1},
volume = {580},
year = {2020}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Halide perovskite materials have promising performance characteristics for low-cost optoelectronic applications. Photovoltaic devices fabricated from perovskite absorbers have reached power conversion efficiencies above 25 per cent in single-junction devices and 28 per cent in tandem devices1,2. This strong performance (albeit below the practical limits of about 30 per cent and 35 per cent, respectively3) is surprising in thin films processed from solution at low-temperature, a method that generally produces abundant crystalline defects4. Although point defects often induce only shallow electronic states in the perovskite bandgap that do not affect performance5, perovskite devices still have many states deep within the bandgap that trap charge carriers and cause them to recombine non-radiatively. These deep trap states thus induce local variations in photoluminescence and limit the device performance6. The origin and distribution of these trap states are unknown, but they have been associated with light-induced halide segregation in mixed-halide perovskite compositions7 and with local strain8, both of which make devices less stable9. Here we use photoemission electron microscopy to image the trap distribution in state-of-the-art halide perovskite films. Instead of a relatively uniform distribution within regions of poor photoluminescence efficiency, we observe discrete, nanoscale trap clusters. By correlating microscopy measurements with scanning electron analytical techniques, we find that these trap clusters appear at the interfaces between crystallographically and compositionally distinct entities. Finally, by generating time-resolved photoemission sequences of the photo-excited carrier trapping process10,11, we reveal a hole-trapping character with the kinetics limited by diffusion of holes to the local trap clusters. Our approach shows that managing structure and composition on the nanoscale will be essential for optimal performance of halide perovskite devices
AU - Doherty,TAS
AU - Winchester,AJ
AU - Macpherson,S
AU - Johnstone,DN
AU - Pareek,V
AU - Tennyson,EM
AU - Kosar,S
AU - Kosasih,FU
AU - Anaya,M
AU - Abdi-Jalebi,M
AU - Andaji-Garmaroudi,Z
AU - Wong,EL
AU - Madeo,J
AU - Chiang,Y-H
AU - Park,J-S
AU - Jung,Y-K
AU - Petoukhoff,CE
AU - Divitini,G
AU - Man,MKL
AU - Ducati,C
AU - Walsh,A
AU - Midgley,PA
AU - Dani,KM
AU - Stranks,SD
DO - 10.1038/s41586-020-2184-1
EP - 366
PY - 2020///
SN - 0028-0836
SP - 360
TI - Performance-limiting nanoscale trap clusters at grain junctions in halide perovskites
T2 - Nature
UR - http://dx.doi.org/10.1038/s41586-020-2184-1
UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000530151300027&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR - https://www.nature.com/articles/s41586-020-2184-1
UR - http://hdl.handle.net/10044/1/83779
VL - 580
ER -