Oxygen Content Modulation Toward Highly Efficient Sb 2 Se 3 Solar Cells.

Vapor-transport deposition (VTD) method is the main technique for the preparation of Sb 2 Se 3 films. However, oxygen is often present in the vacuum tube in such a vacuum deposition process, and Sb 2 O 3 is formed on the surface of Sb 2 Se 3 because the bonding of Sb-O is formed more easily than that of Sb-Se. In this work, the formation of Sb 2 O 3 and thus the carrier transport in the corresponding solar cells were studied by tailoring the deposition microenvironment in the vacuum tube during Sb 2 Se 3 film deposition. Combined by different characterization techniques, we found that tailoring the deposition microenvironment can not only effectively inhibit the formation of Sb 2 O 3 at the CdS/Sb 2 Se 3 interface but also enhance the crystalline quality of the Sb 2 Se 3 thin film. In particular, such modification induces the formation of ( hkl , l = 1)-oriented Sb 2 Se 3 thin films, reducing the interface recombination of the subsequently fabricated devices. Finally, the Sb 2 Se 3 solar cell with the configuration of ITO/CdS/Sb 2 Se 3 /Spiro-OMeTAD/Au achieves a champion efficiency of 7.27%, a high record for Sb 2 Se 3 solar cells prepared by the VTD method. This work offers guidance for the preparation of high-efficiency Sb 2 Se 3 thin-film solar cells under rough-vacuum conditions.