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

• Published in: Journal of materials science. Materials in electronics 2015-02, Vol.26 (2), p.755-761
• Main Authors: Hsu, Feng-Hao, Wang, Na-Fu, Tsai, Yu-Zen, Chien, Ming-Hao, Houng, Mau-Phon
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Optical and Electronic Materials
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-014-2460-7

This study investigates the effects of sputtering power on the performance of p-Ni 1−x O: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 × 10 11  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 Ωcm 2 and shunt resistance ( R sh ): 478.75 Ωcm 2 ]. 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-Ni 1−x O:Li/n-Si HJSCs with a high conversion efficiency and a good temperature coefficient.