de Souza Lucas, F.W.; Welch, A.W.; Baranowski, L.L.; Dippo, P.C.; Hempel, H.; Unold, T.; Eichberger, R.; Blank, B.; Rau, U.; Mascaro, L.H.; Zakutayev, A.:
Effects of Thermochemical Treatment on CuSbS2 Photovoltaic Absorber Quality and Solar Cell Reproducibility. The Journal of Physical Chemistry C 120 (2016), p. 18377-18385
10.1021/acs.jpcc.6b04206
Abstract:
CuSbS2 is a promising nontoxic and earth-abundant photovoltaic
absorber that is chemically simpler than the widely studied Cu2ZnSnS4.
However, CuSbS2 photovoltaic (PV) devices currently have relatively low
efficiency and poor reproducibility, often due to suboptimal material quality
and insufficient optoelectronic properties. To address these issues, here we
develop a thermochemical treatment (TT) for CuSbS2 thin films, which
consists of annealing in Sb2S3 vapor followed by a selective KOH surface
chemical etch. The annealed CuSbS2 films show improved structural quality
and optoelectronic properties, such as stronger band-edge photoluminescence
and longer photoexcited carrier lifetime. These improvements also lead to
more reproducible CuSbS2 PV devices, with performance currently limited by
a large cliff-type interface band offset with CdS contact. Overall, these results
point to the potential avenues to further increase the performance of CuSbS2
thin film solar cell, and the findings can be transferred to other thin film
photovoltaic technologies.
