Tellurium Doping Inducing Defect Passivation for Highly Effective Antimony Selenide Thin Film Solar Cell.

Antimony selenide (Sb 2 Se 3 ) is emerging as a promising photovoltaic material owing to its excellent photoelectric property. However, the low carrier transport efficiency, and detrimental surface oxidation of the Sb 2 Se 3 thin film greatly influenced the further improvement of the device efficiency. In this study, the introduction of tellurium (Te) can induce the benign growth orientation and the desirable Sb/Se atomic ratio in the Te-Sb 2 Se 3 thin film. Under various characterizations, it found that the Te-doping tended to form Sb 2 Te 3 -doped Sb 2 Se 3 , instead of alloy-type Sb 2 (Se,Te) 3 . After Te doping, the mitigation of surface oxidation has been confirmed by the Raman spectra. High-quality Te-Sb 2 Se 3 thin films with preferred [hk1] orientation, large grain size, and low defect density can be successfully prepared. Consequently, a 7.61% efficiency Sb 2 Se 3 solar cell has been achieved with a V OC of 474 mV, a J SC of 25.88 mA/cm 2 , and an FF of 64.09%. This work can provide an effective strategy for optimizing the physical properties of the Sb 2 Se 3 absorber, and therefore the further efficiency improvement of the Sb 2 Se 3 solar cells.