Lowest Open-Circuit Voltage Deficit Achievement to Attain High Efficient Antimony Selenosulfide Solar Cells

Antimony selenosulfide (Sb-2(S,Se)(3)) solar cells bear great potential for sustainable photovoltaic technology, attributed to their excellent semiconductor properties. Despite the encouraging breakthroughs, the efficiency of Sb-2(S,Se)(3 )solar cells still leaves much room for improvement due to the large open-circuit voltage (V-OC) deficit (the radiative V-OC limit minus the high VOC). Herein, ammonium sulfide ((NH4)(2)S) solution is utilized to treat Sb-2(S,Se)(3 )films to tailor their surface properties. The disappearance of the hole defect (H1) and the decrease of the defect concentration of hole defect (H2) confirm that non-radiative recombination is suppressed greatly. Photovoltage decay lifetime is greatly increases from 67.9 to 297.9 mu s. The upshifted valence band maximum optimizes the energy level alignment between the p-n heterojunction, enhancing the carrier transport. Remarkably, this treatment yields a record lowest V-OC deficit of 0.49 V by now, and the best device with 10.41% efficiency, ca. 25% improvement over the control device (8.35%). This study provides valuable insight into reducing the V-OC deficit in solar cells and related photoelectronic devices by minimizing non-radiative recombination, and also presents a great potential strategy to achieve the lowest V(OC )deficit.