Effect of the thickness on the optoelectronic properties of SnS films and photovoltaic performance of SnS/i-a-Si/n-a-Si solar cells

Different thick orthorhombic SnS films were successfully fabricated by sulfurization of various sputtered different thick Sn precursor layers. All the absorption coefficients of different thick SnS films are higher than 2 × 104 cm−1 in the visible light region of 400–800 nm, and the direct band gaps of these SnS films were estimated to be about 1.2 eV. Furthermore, SnS/i-a-Si/n-a-Si solar cells with 205-, 420-, 635-, 845- and 1,060-nm-thick SnS-absorber layers were fabricated, and the 845-nm-thick SnS-absorber-based SnS/i-a-Si/n-a-Si solar cell shows the highest conversion efficiency of 0.42 %, a short-circuit current density of 2.4 mA/cm2, and an open-circuit voltage of 362 mV.