Highly efficient bifacial semitransparent perovskite solar cells based on molecular doping of CuSCN hole transport layer

Hou Shixin^{1, 2, 3, 4, 5}, Shi Biao^{1, 2, 3, 4, 5}, Wang Pengyang^{1, 2, 3, 4, 5, †}, Li Yucheng^{1, 2, 3, 4, 5}, Zhang Jie^{1, 2, 3, 4, 5}, Chen Peirun^{1, 2, 3, 4, 5}, Chen Bingbing^{1, 2, 3, 4, 5}, Hou Fuhua^{1, 2, 3, 4, 5}, Huang Qian^{1, 2, 3, 4, 5}, Ding Yi^{1, 2, 3, 4, 5}, Li Yuelong^{1, 2, 3, 4, 5}, Zhang Dekun^{1, 2, 3, 4, 5}, Xu Shengzhi^{1, 2, 3, 4, 5}, Zhao Ying^{1, 2, 3, 4, 5}, Zhang Xiaodan^{1, 2, 3, 4, 5, ‡}

(a) J–V curves from forward-biased (FB) to short-circuit (SC) of the optimal CsFAMA PSCs using CuSCN or F4TCNQ-doped CuSCN as HTMs under 1-sun illumination. The insert is the cross-sectional scanning electron microscope image of PSCs; (b) EQE and integrated J_sc spectra of the corresponding optimal devices. (c) Normalized PCE of PSC (undoped CuSCN and doped CuSCN) as a function of aging time at 25 °C in N₂ atmosphere. (d) Statistics of PCE for CuSCN and F4TCNQ-doped CuSCN devices (25 cells are included).