Correlated Mapping of Raman Spectroscopy and Cathodoluminescence of Emerging Absorber Bournonite (CuPbSbS3)

Bournonite (CuPbSbS3) is an emerging absorber material for solar cells. There is little literature on some of its fundamental structural and optical properties. We report the first complete Raman spectra of bournonite as well as the first luminescence signal. A chosen area has been mapped with both Raman spectra and cathodoluminescence (CL) to investigate the structural and optical uniformity. Raman mapping reveals a new secondary phase, tetrahedrite, but otherwise a uniform compositional thin-film. CL mapping reveals slight redshift at grain boundaries (GBs). Preliminary devices made with a bournonite absorber layer show rectification under standard test conditions.