In situ sulfurization to generate Sb 2 (Se 1 − x S x ) 3 alloyed films and their application for photovoltaics

Because of its tunable band gap and band position, Sb 2 (Se 1 −  x S x ) 3 (0 ≤  x  ≤ 1) is a promising light‐absorbing material for photovoltaic device applications. However, no systematic study on the synthesis and characterization of single‐phase polycrystalline Sb 2 (Se 1 −  x S x ) 3 thin films has been reported. Through introducing in situ sulfurization into the rapid thermal evaporation process, a series of single‐phase, highly crystalline Sb 2 (Se 1 −  x S x ) 3 films with x  = 0.09, 0.20, 0.31, and 0.43 were successfully obtained, with the corresponding band gap, band position and film morphology fully revealed. Futhermore, solar cells with superstrate ITO/CdS/Sb 2 (Se 1 −  x S x ) 3 /Au structure were fabricated and carefully optimized. Finally, a champion device having 5.79% solar conversion efficiency was obtained employing uniform Sb 2 (Se 0.80 S 0.20 ) 3 absorber layer. Our experimental investigation confirmed that Sb 2 (Se 1 −  x S x ) 3 is indeed a very promising absorber material worth further optimization. Copyright © 2016 John Wiley & Sons, Ltd.