Improved SnS:Mg thin film solar cells achieved by reduced recombination rate

Abstract

Mg-doped SnS (SnS:Mg) films have been synthesized using the alovera gel extract via the sol–gel process. XRD showed the formation of SnS and SnS:Mg films. The 2 % SnS:Mg film showed large grain size (41 nm) and d-spacing (2.84 Å) for the (111) plane. Raman spectra showed that peaks are shifted by doping. SEM images showed that particles are spherical in shape and large at 2 % Mg doping. According to UV–Vis, small bandgap energy (1.35 eV), high refractive index (2.90), and large dielectric constants (4.04) are observed at 2 % Mg doping. SnS exhibits a high-intensity photoluminesence (PL) band at 1.74 eV, and defective peaks are removed by doping. The solar cells of these films are prepared with the geometry FTO/TiO2/SnS/spiro-OMeTAD/Au. The cell fabricated with 2 % SnS:Mg showed a large fill factor (0.72), short-circuit current density (6.21 mA-cm−2), open circuit voltage (0.67 V), and efficiency (3.0 %). This is a low-cost, simple-to-make solar cell with a long lifespan due to the lack of chemical corrosion.