Oxygen Content Modulation Toward Highly Efficient SbSe Solar Cells.

Vapor-transport deposition (VTD) method is the main technique for the preparation of SbSe films. However, oxygen is often present in the vacuum tube in such a vacuum deposition process, and SbO is formed on the surface of SbSe because the bonding of Sb-O is formed more easily than that of Sb-Se. In this work, the formation of SbO and thus the carrier transport in the corresponding solar cells were studied by tailoring the deposition microenvironment in the vacuum tube during SbSe film deposition. Combined by different characterization techniques, we found that tailoring the deposition microenvironment can not only effectively inhibit the formation of SbO at the CdS/SbSe interface but also enhance the crystalline quality of the SbSe thin film. In particular, such modification induces the formation of (, = 1)-oriented SbSe thin films, reducing the interface recombination of the subsequently fabricated devices. Finally, the SbSe solar cell with the configuration of ITO/CdS/SbSe/Spiro-OMeTAD/Au achieves a champion efficiency of 7.27%, a high record for SbSe solar cells prepared by the VTD method. This work offers guidance for the preparation of high-efficiency SbSe thin-film solar cells under rough-vacuum conditions.