Stable and low resistive zinc contacts for SnS based optoelectronic devices

• Nanocrystalline SnS films were deposited using thermal evaporation method.
• Contact behavior of Zn with SnS films was investigated.
• SnS/Zn structures exhibited low electrical resistivity and good Ohmic behavior.
• Activation energy of SnS films is found to be 0.24 eV.

The contact behavior of tin mono sulfide (SnS) nanocrystalline thin films with zinc (Zn) and silver (Ag) contacts was studied. SnS films have been deposited on glass substrates by thermal evaporation technique at a growth temperature of 300 °C. The as-grown SnS films composed of vertically aligned nanocrystallites with a preferential orientation along the <010> direction. SnS films exhibited excellent chemical stoichiometry and direct optical band gap of 1.96 eV. These films also exhibited excellent Ohmic characteristics and low electrical resistivity with Zn contacts. The observed electrical resistivity of SnS films with Zn contacts is 22 times lower than that of the resistivity with Ag contacts. The interfacing analysis reveals the formation of conductive Zn–S layer between SnS and Zn as interfacial layer.