Do grain boundaries dominate non-radiative recombination in CH3NH3PbI3perovskite thin films?
Here, we examine grain boundaries (GBs) with respect to non-GB regions (grain surfaces (GSs) and grain interiors (GIs)) in high-quality micrometer-sized perovskite CH3NH3PbI3(or MAPbI3) thin films using high-resolution confocal fluorescence-lifetime imaging microscopy in conjunction with kinetic modeling of charge-transport and recombination processes. We show that, contrary to previous studies, GBs in our perovskite MAPbI3thin films do not lead to increased recombination but that recombination in these films happens primarily in the non-GB regions (i.e., GSs or GIs). We also find that GBs in these films are not transparent to photogenerated carriers, which is likely associated with a potential barrier at GBs. Even though GBs generally display lower luminescence intensities than GSs/GIs, the lifetimes at GBs are no worse than those at GSs/GIs, further suggesting that GBs do not dominate non-radiative recombination in MAPbI3thin films.
Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA. Jao.vandeLagemaat@nrel.gov Kai.Zhu@nrel.gov.
Mengjin
M
Yang
Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA. Yining.Zeng@nrel.gov.
Yining
Y
Zeng
Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA. Jao.vandeLagemaat@nrel.gov Kai.Zhu@nrel.gov.
Zhen
http://orcid.org/0000-0003-1177-2818
Z
Li
Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA. Jao.vandeLagemaat@nrel.gov Kai.Zhu@nrel.gov.
Dong Hoe
DH
Kim
Material Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA.
Chun-Sheng
CS
Jiang
Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA. Jao.vandeLagemaat@nrel.gov Kai.Zhu@nrel.gov.
Jao
http://orcid.org/0000-0001-5851-6163
J
van de Lagemaat
Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA. Jao.vandeLagemaat@nrel.gov Kai.Zhu@nrel.gov.
Kai
K
Zhu