Minskade rekombinationsförluster i solceller baserade på Cu2ZnSnS4

Tidsperiod: 2016-01-01 till 2019-12-31

Projektledare: Charlotte Platzer Björkman

Finansiär: Vetenskapsrådet

Bidragstyp: Projektbidrag

Budget: 3 280 000 SEK

The present project concerns recombination analysis in thin film solar cells based on CZTS (Cu2ZnSnS4). For today´s state of the art devices the main limitation relates to the open circuit voltage, Voc which in turn is limited by recombination at different positions in the device. One potential high recombination position is the CZTS/CdS heterojunction interface. Another source of loss is the bulk, where recent results suggest a reduced effective bandgap for recombination through potential fluctuations and clustering from high defect densities. One hypothesis behind the present proposal is however that interface recombination is limiting Voc more than currently believed. Recombination will be studied by combining temperature dependent current-voltage measurements with suns-Voc measurements, capacitance, quantum efficiency and photoluminescence. Controlled variations in interface properties or bulk properties in fabricated devices will the basis for the recombination analysis. Development of device models in 1 and 2 dimensions will be used to support interpretation of device data. Reduction of recombination in CZTS is essential to improve performance. The methodology for studying recombination losses is currently not satisfactory and hinders the understanding of recombination losses. The aim of this project is to improve the methodology and find efficient routes to minimize recombination.