Stability and Efficiency Enhancement of Antimony Selenosulfide Solar Cells with Inorganic SnS‐Modified Nickel Oxide Hole Transport Materials

Abstract

Antimony selenosulfide (Sb2(S,Se)3) has been emerging as a promising light absorber owing to its tunable bandgap (1.1–1.7 eV), high absorption coefficient (>105 cm−1), and excellent phase and environmental stability. Lithium salt‐doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxy‐phenylamine)‐9,9′‐spirobifluorene (spiro‐OMeTAD) has been generally used as the hole transport layer (HTL) in these high‐efficiency antimony selenosulfide solar cells so far. However, the lithium‐ion reactions and migration in this HTL may cause serious challenges for the stability of these solar cells. Herein, stable and low‐cost tin monosulfide (SnS) nanoparticles surface‐modified nickel oxide (NiOx) as an inorganic hole transport layer to fabricate highly efficient and stable all‐inorganic solar cells is developed. It is found that NiOx films not only demonstrate a higher conductivity but also form better energy band alignment after SnS surface treatment. Consequently, the power conversion efficiency of the full inorganic Sb2(S,Se)3 solar cells increases from 4.85% to 6.41%. Most importantly, the devices also demonstrate much improved thermal, moisture, and long‐term stabilities as compared to the solar cells with spiro‐OMeTAD hole transport layer.