Cadmium and Zinc‐Doped p‐type Sb ₂ Se ₃ Single Crystals and Solar Cells

Achieving controlled p‐type doping in Sb 2 Se 3 is critical for its development as a photovoltaic absorber. In this work, the incorporation of Cd and Zn as extrinsic dopants in Sb 2 Se 3 single crystals and thin films, with concentrations ranging from 10 16 to 10 20 , is investigated. Both dopants successfully induce p‐type conductivity, but Cd consistently yields lower resistivities and avoids compensation over a wider range of dopant concentrations. Cd‐doped Sb 2 Se 3 single crystals exhibit hole densities exceeding 10 , while thin films achieve over 10 , values suitable for efficient solar cell operation. A shallow 22 meV acceptor level appears to be compensated by a deeper lying state around 389 meV, which is intrinsic to Sb 2 Se 3 and limits the achievable free hole concentration. Despite this, solar cells fabricated using Cd‐doped Sb 2 Se 3 (at 10 ) show enhancements in open‐circuit voltage by ≈60 and ≈20 mV for devices prepared via thermal evaporation and close‐spaced sublimation respectively, relative to n‐type Cl‐doped Sb 2 Se 3 . These results establish Cd as a promising dopant for enabling robust p‐type conductivity and enhancing the photovoltaic performance of Sb 2 Se 3 ‐based devices.