Structural and opto-electronic features of pulsed laser ablation grown Cu2ZnSnS4 films for photovoltaic applications

We report synthesis of Cu2ZnSnS4 thin films of kesterite structure by sulfurization of pulsed laser deposited (PLD) CuZnSn composite films at optimized temperature. These films show sharp optical absorption edge in the range of 1.4-1.6 eV, when prepared under optimized conditions of deposition and sulfurization. In general, the processed films are found to be non-stoichiometric with deficiency of S and excess of Zn. Electrical conductivity measurements in the temperature range 50-300 K reveal hopping transport with activation energies ≤20 meV at T < 80 K and a room temperature resistivity varying from 0.1 to 2.7 Ω-cm.