Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6534276 | Solar Energy Materials and Solar Cells | 2018 | 10 Pages |
Abstract
Kesterite Cu2ZnSn(SxSe1âx)4 is an attractive earth-abundant material for low-cost thin film photovoltaics with the capability to achieve power production in the terawatt range and therefore to supply a significant part of the global electricity needs. Despite its advantageous optical and electrical properties for photovoltaic applications, the large band tailing causes voltage losses that limit the efficiency of kesterite-based devices. Here we show that the band-tailing originates mainly from band-gap fluctuations attributable to chemical composition variations at nanoscale; while electrostatic fluctuations play a lesser role. Absorption measurement reveal that the Cu-Zn disorder, always present in kesterite Cu2ZnSn(SxSe1âx)4, is not the main source of the large band tailing. Instead defect clusters having a significant impact on the band-edge energies, e.g. [2CuZnâ+SnZn2+], are proposed as the main origin for the kesterite band tail.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Catalysis
Authors
G. Rey, G. Larramona, S. Bourdais, C. Choné, B. Delatouche, A. Jacob, G. Dennler, S. Siebentritt,