Dopant-free star-shaped hole-transport materials for efficient and stable perovskite solar cells

• Published in: Dyes and pigments 2017-01, Vol.136, p.273-277
• Main Authors: Zhang, Fei, Zhao, Xiaoming, Yi, Chenyi, Bi, Dongqin, Bi, Xiangdong, Wei, Peng, Liu, Xicheng, Wang, Shirong, Li, Xianggao, Zakeeruddin, Shaik Mohammed, Grätzel, Michael
• Format: Article
• Language: English
• Subjects: Dopant-free; Hole transport material; Perovskite; Solar cell; Triphenylamine
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2016.08.002

Two star-shaped TPA-based small-molecule materials (Z1012 and Z1013) were designed and synthesized in this paper. These molecules show high hole mobility and suitable energy levels for CH3NH3PbI3-based perovskite solar cells. Photovoltaic cells based on the Z1013 without any dopants or additives achieve an excellent power conversion efficiency (PCE) of 15.4%, which is comparable to devices based on state-of-art p-doped spiro-OMeTAD. Moreover, the devices based on these two HTMs show much better stability than that of devices based on spiro-OMeTAD when aging in ambient air both at room temperature and 80 °C. These results demonstrate that star-shape TPAs could be excellent dopant-free HTMs for perovskite solar cells and hold promise to replace the p-doped spiro-OMeTAD, which is important for the fabrication of cost-effective and stable devices. Two star-shaped triphenylamine (TPA) based small-molecules were synthesized and used as dopant-free hole-transport materials for efficient perovskite solar cells. [Display omitted] •Star-shaped Z1012 and Z1013 were applied in perovskite solar cell as HTMs.•Photovoltaic cells based on Z1013 without dopants achieve an excellent PCE of 15.4%.•The devices based on these two HTMs show better stability when aging in ambient air.