Hot-carrier cooling in lead-bromide perovskite materials
File(s)
Published version
Author(s)
Type
Conference Paper
Abstract
Lead-halide perovskites are currently the highest-performing solution-processable semiconductors for solar energy conversion, with record efficiencies rapidly approaching that of the Shockley-Queisser limit for single-junction solar cells. Further progress in the development of lead-halide perovskite solar cells must overcome this limit, which largely stems from the ultrafast relaxation of high-energy hot carriers above the bandedge. In this contribution, we use a highly-specialized pump-push-probe technique to unravel the key parameters which control hot carrier cooling in bulk and nanocrystal (NC) lead bromide perovskites with different material composition, NC diameter and surface treatment. All samples exhibit slower cooling for higher hot carrier densities, which we assign to a phonon bottleneck mechanism. By comparing this density-dependent cooling behavior in the different samples, we find that the weak quantum confinement of electronic states and the surface defects in the NCs play no observable role in the hot carrier relaxation. Meanwhile, in accordance with our previous observations for bulk perovskites, we show that the cation plays a critical role towards carrier cooling in the perovskite NCs, as evidenced by the faster overall cooling in the hybrid FAPbBr3 NCs with respect to the all-inorganic CsPbBr3 NCs. These observations highlight the crucial role of the cations toward the phononic properties of lead-halide perovskites, and further point towards the defect tolerance of these emerging solution-processed semiconductors.
Date Issued
2019-09-09
Date Acceptance
2019-08-11
Citation
Proceedings of SPIE, 2019, 11084
ISBN
9781510628618
ISSN
0277-786X
Publisher
Society of Photo-optical Instrumentation Engineers
Journal / Book Title
Proceedings of SPIE
Volume
11084
Copyright Statement
© 2019 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
Sponsor
The Royal Society
Grant Number
UF130178
Source
Physical Chemistry of Semiconductor Materials and Interfaces XVIII
Publication Status
Published
Start Date
2019-08-11
Finish Date
2019-08-15
Coverage Spatial
San Diego, California, United States
Date Publish Online
2019-09-09