Lead antimony sulfides as potential solar absorbers for thin film solar cells

In an effort to prepare thin films of novel semiconductor materials that contain only cost effective, abundant, and relatively less-toxic materials, lead antimony sulfides films have been prepared. Herein, we report the thin film preparation of semseyite (Pb₉Sb₈S₂₁) via annealing of precursor films under sulfur vapor. Pb/Sb alloy precursor films suffered substantial changes in stoichiometry and produced rough films, whereas precursor films composed of multilayers of PbS and amorphous (Sb,S) produced smooth and compact phase-pure films composed of fine grains. Optical measurements indicated a direct band gap of 1.93 eV and a strong absorption coefficient of 1.0 × 10⁵ cm^− 1.