Trimeric carbazole phosphonic acid hole-transporting molecules with robust processability enhance the efficiency of organic solar cells to 20%

Tianqi Chen, Yunxin Zhang, Wenkai Zhao, Yanyi Zhong, Wanying Feng, Baofa Lan, Xuehang Dong, H. J. Yang, Jiangbin Zhang, Kai Han, Guankui Long, Bin Kan, Yongsheng Chen