In situ growth of graphene on both sides of a Cu-Ni alloy electrode for perovskite solar cells with improved stability

作者：Lin, Xuesong; Su, Hongzhen; He, Sifan; Song, Yenan; Wang, Yanbo^*; Qin, Zhenzhen; Wu, Yongzhen; Yang, Xudong; Han, Qifeng; Fang, Junfeng; Zhang, Yiqiang; Segawa, Hiroshi; Graetzel, Michael; Han, Liyuan^*

来源：Nature Energy, 2022, 7(6): 520-527.

DOI：10.1038/s41560-022-01038-1

• HIGH-PERFORMANCE
• DEGRADATION
• GOLD

The instability of rear electrodes undermines the long-term operational durability of efficient perovskite solar cells. Here, a composite electrode of copper-nickel (Cu-Ni) alloy stabilized by in situ grown bifacial graphene is designed. The alloying makes the work function of Cu suitable for regular perovskite solar cells. Cu-Ni is the ideal substrate for preparing high-quality graphene via chemical vapour deposition, which simultaneously protects the device from oxygen, water and reactions between internal components. To rivet the composite electrode with the semi-device, a thermoplastic copolymer is applied as an adhesive layer through hot pressing. The resulting devices achieve power conversion efficiencies of 24.34% and 20.76% (certified 20.86%) with aperture areas of 0.09 and 1.02 cm(2), respectively. The devices show improved stability: 97% of their initial efficiency is retained after 1,440 hours of a damp-heat test at 85 degrees C with a relative humidity of 85%; 95% of their initial efficiency is retained after 5,000 hours at maximum power point tracking under continuous 1 sun illumination. @@@ The instability of contact layers for perovskite solar cells under operating conditions limits the deployment of the technology. Now, Lin et al. develop a Cu-Ni electrode sandwiched between in situ-grown graphene protective layers, enabling solar cells with improved stability under light, humidity and high temperature.

• 单位
  华东理工大学; 郑州大学; 上海交通大学