Tunable Quasi-One-Dimensional Ribbon Enhanced Light Absorption in Sb₂Se₃ Thin-film Solar Cells Grown by Close-Space Sublimation

The non-cubic antimony chalcogenides, i.e., Sb₂Se₃, formed by quasi-one-dimensional ribbons can enhance light absorption and carrier transport by tuning the ribbon direction using the close-space sublimation (CSS) deposition. The improved device performance is found to be associated with the ribbon direction, which was investigated with theoretical calculation and experimental optical measurement in the Sb₂Se₃ films and devices. Decent device efficiency could be achieved when the ribbons were tuned to be as normal to the substrate as possible. The substrate temperature and film thickness are critical for the fine-tuning of ribbon orientations during the CSS deposition. Our results show that [211]-preferred orientation leads to the minimum series resistance and highest light absorbance in the device. This observation demonstrates that Sb₂Se₃-like quasi-one-dimensional materials with van der Waals boundaries can achieve scalable production at low cost and hold great potential for next-generation solar cell using the recently developed vapor transport deposition technology.