Efficiency Improvement of NiOx‐Based Hole Transport Layers in Passivated Contact Crystalline Silicon Solar Cells. - Zhang, Hai; Kang, Qian; Wang, Yanhao; Li, Jingjie; Liu, Siyi; Yan, Hui; Zhang, Shanting; Li, Dongdong; Zhang, Yongzhe (Solar RRL, 2025)