[Tang, Cun; Yang, Di; Wu, Yunrou; Wang, Hongqin; Huang, Mingju; Li, Jie; Wang, Dongyang; Chen, Ke; Liu, Weitao] Henan Univ, Ctr Phys Low Dimens Mat, Sch Phys & Elect, Henan Joint Int Res Lab New Energy Mat & Devices, Kaifeng 475004, Peoples R China.
[Zhan, Guangming] Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
[Wang, Huan] Nankai Univ, Coll Chem, Renewable Energy Convers & Storage Ctr RECAST, Key Lab Adv Energy Mat Chem,Minist Educ, Tianjin 300071, Peoples R China.
[Liu, Kaihui] Peking Univ, Sch Phys, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China.