The importance of back contact modification in Cu2ZnSnSe4 solar cells: The role of a thin MoO2 layer

Cu2ZnSn(SxSe1-x)4 (CZTSSe) photovoltaic absorbers could be the earth-abundant and low toxicity replacement for the already commercialized CuIn1-xGaxSe2 (CIGS) thin film technology. In order to make this possible, specific research efforts applied to the bulk, front and back interfaces must be perfor...

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Detalhes bibliográficos
Autores: López-Marino, S., Espíndola-Rodríguez, M., Sánchez, Y., Alcobé, X., Oliva, Florian, Xie, H., Neuschitzer, M., Giraldo, S., Placidi, M., Caballero, Raquel, Izquierdo-Roca, V., Pérez-Rodríguez, A., Saucedo, E.
Tipo de documento: artigo
Data de publicação:2016
País:España
Recursos:Universidad Autónoma de Madrid
Repositório:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglês
OAI Identifier:oai:repositorio.uam.es:10486/672739
Acesso em linha:http://hdl.handle.net/10486/672739
https://dx.doi.org/10.1016/j.nanoen.2016.06.034
Access Level:Acceso aberto
Palavra-chave:Back contact
Cu ZnSnSe
MoO2
MoSe2
Solar cells
Física
Descrição
Resumo:Cu2ZnSn(SxSe1-x)4 (CZTSSe) photovoltaic absorbers could be the earth-abundant and low toxicity replacement for the already commercialized CuIn1-xGaxSe2 (CIGS) thin film technology. In order to make this possible, specific research efforts applied to the bulk, front and back interfaces must be performed with the aim of improving CZTSSe performance. In this paper the importance of back contact modification to obtain high efficiency Cu2ZnSnSe4 (CZTSe) solar cells and to increase a paramount and limiting parameter such as VOC is highlighted. Several Mo configurations (monolayer, bi-layer and tri-layer) with different electrical and morphological properties are investigated in CZTSe solar cells. An optimum tri-layer configuration in order to minimize overselenization of the back contact during thermal annealing while keeping reasonable electrical features is defined. Additionally, a thin intermediate MoO2 layer that results in a very effective barrier against selenization and innovative way to efficiently assist in the CZTSe absorber sintering is introduced. The use of this layer enhances grain growth and subsequently the efficiency of solar cells increases via major VOC and FF improvement. An efficiency increase from 7.2% to 9.5% is obtained using a Mo tri-layer with a 20 nm intermediate MoO2 layer