Transport mechanisms and photovoltaic characteristics of p-SxSe100−x/n-Si heterojunctions

The dark current-voltage characteristics of p-SxSe100−x/n-Si heterojunctions, with x = 0, 2.5, 5.8 and 7.28 at.% S have been investigated in a temperature range from 303 to 383 K. The operating conduction mechanisms were found to be the thermionic-assisted tunnelling and pure tunnelling for low and high forward bias, respectively. Under reverse biasing, the operating conduction mechanism is the generation recombination mechanism. Analysis of the photovoltaic characteristics at room temperature and under illumination of ∼477 Wm−2 leads to the determination of some solar cell parameters, such as, the short circuit current density (JSC ≈ 165, 140, 116.7 and 103.3 A/m2), the open-circuit voltage (Voc ≈ 0.36, 0.35, 0.32 and 0.31 V), the fill factor (FF ≈ 0.344, 0.372, 0.360 and 0.378) and the power conversion efficiency (η ≈ 4.278, 3.816, 2.814 and 2.534%) for x = 0, 2.5, 5.8 and 7.28 at. % S, respectively.