Structural, optical and electrical studies of DC-RF magnetron co-sputtered Cu, In & Ag doped SnS thin films for photovoltaic applications.

• First report on Cu, In and Ag doped SnS thin films using co-sputtering with ISST of 400 °C. • The substitutional doping of Cu2+, In3+ and Ag2+ ions in SnS lattice sites is studied. • Band gap, Eg = 1.36 eV and absorption coefficient, α = 3.5 × 104 cm-1 achieved for Cu 4.8 % doping. • Resistivity, ρ = 90 Ωcm and carrier concentration P = 2.3 × 1017 cm-3 achieved for Cu 4.8% doping. This work reports the tuning of optical and electrical properties of SnS through the incorporation of Cu, In and Ag atom without altering its chemical and crystal structural properties, using DC-RF magnetron co-sputtering technique with an in-situ substrate temperature of 400 °C. Doping is increased up to ~10% by varying the DC sputtering voltage as evident from EDAX analysis. Morphological studies show the variation in surface morphology, particle size and surface roughness due to the incorporation of dopant cation into SnS lattice sites. Film with optimized doping of ~5% resulted the substitutional doping of dopant cations (Cu2+, In3+ and Ag2+) into SnS lattice sites which resulted an improved absorption coefficient and hall carrier concentration with a decrease in band gap and electrical resistivity. Hall measurement studies of Cu 4.8% doped SnS film shows the p-type conductivity with lowest electrical resistivity of 90 Ω cm and improved carrier concentration of 1017 cm−3. [ABSTRACT FROM AUTHOR]