Efficient coaxial n-i-p heterojunction Sb2S3 solar cells

Abstract Sb 2 S 3 is a kind of emerging light harvesting material for solar cell applications, where both planar and nanostructured configurations are of great interests in the device investigations. This work conducts a comparative study on heterojunction configuration of Sb 2 S 3 solar cells with regard to different CdS substrates. By controlling the hydrothermal durations of Sb 2 S 3 film, the CdS nanorod enables the fabrication of coaxial n-i-p heterojunction Sb 2 S 3 solar cells. It is demonstrated that coaxial heterojunction can effectively improve carrier transport compared with planar heterojunction, leading to the fill factor increasing from 51.3% to 62.7% with regard to different degree of pore filling. Mechanism investigations suggest that both deep-level defect type and defect density in coaxial heterojunction device are significantly reduced, which further reduces carrier recombination in Sb 2 S 3 film, clearly manifesting that the coaxial heterojunction configuration reduces the series resistance and enables efficient carrier transport. In addition, the coaxial heterojunction device presents a remarkably improved stability compared with planar heterojunction device. The research offers a fundamental guideline for the fabrication of efficient antimony chalcogenide solar cells.