Effect of sputtering power on the performance of p-Ni1−xO:Li/n-Si heterojunction solar cells

Abstract

This study investigates the effects of sputtering power on the performance of p-Ni1−xO:Li/n-Si heterojunction solar cells (HJSCs). The results of this study indicate a strong dependence of the cell characteristics on the sputtering power. Extremely high or low sputtering power generates higher interface state density (D it ), resulting in the lowering of open circuit voltage (V oc ) and fill factor (FF). The cell fabricated at a sputtering power of 100 W has the lowest D it of 7.08 × 1011 cm−2 eV−1, corresponding to the highest conversion efficiency (η) of 4.30 % [short circuit current density (J sc ): 18.06 mA cm−2, V oc : 390 mV, FF: 61.1 %, series resistance (R s ): 4.3 Ωcm2 and shunt resistance (R sh ): 478.75 Ωcm2]. Furthermore, the cell exhibits a considerably poor temperature coefficient of −0.70 %/ °C (J sc : +0.07 %/°C, V oc : −0.52 %/°C and FF: −0.29 %/°C) when compared with conventional solar cells. Further improvement in the D it of the cell is highly imperative for developing p-Ni1−xO:Li/n-Si HJSCs with a high conversion efficiency and a good temperature coefficient.