Back to Search Start Over

Hot electron relaxation in Type-II quantum wells.

Authors :
Wang, Hua
Borunda, Mario F.
Mullen, Kieran J.
Source :
Journal of Chemical Physics; 5/28/2023, Vol. 158 Issue 20, p1-8, 8p
Publication Year :
2023

Abstract

A photovoltaic device fabricated with conventional zincblende materials can use the Type-II quantum well structure, which spatially separates electrons and holes, to reduce their recombination rate. In order to obtain higher power conversion efficiency, it is desirable to preserve more energetic carriers by engineering a phonon "bottleneck," a mismatch between the gaps in the well and barrier phonon structure. Such a mismatch leads to poor phonon transport and therefore prevents energy from leaving the system in the form of heat. In this paper, we perform a superlattice phonon calculation to verify the "bottleneck" effect and build on this a model to predict the steady state of the hot electrons under photoexcitation. We describe the electrons and phonons with a coupled Boltzmann equation system and numerically integrate it to get the steady state. We find that inhibited phonon relaxation does lead to a more out-of-equilibrium electron distribution and discuss how this might be enhanced. We examine the different behaviors obtained for various combinations of recombination and relaxation rates and their experimental signatures. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00219606
Volume :
158
Issue :
20
Database :
Complementary Index
Journal :
Journal of Chemical Physics
Publication Type :
Academic Journal
Accession number :
164087960
Full Text :
https://doi.org/10.1063/5.0134031