Synthesis of Cu2SnS3, Cu3SnS4, and Cu4SnS4 thin films by sulfurization of SnS-Cu layers at a selected temperature and /or Cu layers thickness

The effect of boron doping on the optical, morphological and structural properties of Cu3SbS3 thin films prepared via spin coating

For the first time, boron doped Cu3SbS3 thin films were produced via spin coating method. Boron doped Cu3SbS3 thin films will provide new dimensions for the design of environmentally friendly, low cost and highly efficient solar cell absorber layer.

Effect of the stacking order, annealing temperature and atmosphere on crystal phase and optical properties of Cu2SnS3

Cu₂SnS₃ (CTS) is emerging as a promising absorber for the next generation thin film solar cells (TFSC) due to its excellent optical and electronic properties, earth-abundance and eco-friendly elemental composition. In addition, CTS can be used as precursor films for the Cu₂ZnSnS₄ (CZTS) synthesis. The optical properties of CTS are influenced by stoichiometry, crystalline structure, secondary phases and crystallite size. Routes for obtaining CTS films with optimized properties for TFSC are still being sought. Here, the CTS thin films synthesized by magnetron sputtering on soda lime glass (SLG) using Cu and SnS₂ targets in two different stacks, were studied. The SLG\Cu\SnS₂ and SLG\SnS₂\Cu stacks were annealed in S and Sn + S atmospheres, at various temperatures. Both stacks show a polymorphic structure, and higher annealing temperatures favor the monoclinic CTS phase formation. Morphology is influenced by the stacking order since a SnS₂ top layer generates several voids on the surface due to the evaporation of SnS, while a Cu top layer provides uniform and void-free surfaces. The films in the copper-capped stack annealed under Sn + S atmosphere have the best structural, morphological, compositional and optical properties, with tunable band gaps between 1.18 and 1.37 eV. Remarkably, secondary phases are present only in a very low percent (< 3.5%) in samples annealed at higher temperatures. This new synthesis strategy opens the way for obtaining CTS thin films for solar cell applications, that can be used also as intermediary stage for CZTS synthesis.