Lifetime improvement for high efficiency Cu<inf>2</inf>ZnSnS<inf>4</inf> submodules

Abstract

Photoluminescence (PL) lifetime of 36 ns on Cu <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ZnSnS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> absorber was achieved by optimizing absorber formation. The high quality absorber enabled us to achieve 9.2% efficiency Cu <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ZnSnS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> submodule. Comparison between the PL lifetime and atomic composition showed lower Cu/Sn ratio resulted in longer lifetime. The lower Cu/Sn ratio made bandgap higher and voltage deficit lower. The PL intensity mapping accelerated the quality clarification of the various absorbers and contributed to the achievement of high efficiency Cu <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ZnSnS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> submodules.