Influence of selenium growth condition on the photovoltaic conversion efficiency of Sb2Se3 as the solar cell absorption layer

The influences of the selenium (Se) growth condition on the electronic level structure including deep defects and further on the photovoltaic conversion efficiency of antimony selenide (Sb 2 Se 3 ) as the solar cell absorber layer are investigated by controlling the Se powder content during the vapor transport deposition process. The detailed characterizations including X-ray diffraction, Raman, optical absorption and photoluminescence reveal that the deep defects including the Se vacancies on the Sb 2 Se 3 surface are largely reduced, and the efficiency of Sb 2 Se 3 solar cells can be significantly improved, e.g., by about 31% from 5.1% to 6.7% after adding excessive Se powder during the growth process. This result may provide a basic guideline for improving the efficiency of Sb 2 Se 3 solar cells during the growth process of the Sb 2 Se 3 absorption layer.