Intramolecular p-i-n junction photovoltaic device based on selectively doped carbon nanotubes

• Published in: Nano energy 2017-02, Vol.32, p.280-286
• Main Authors: Chen, Changxin, Song, Chuanjuan, Yang, Junru, Chen, Dingqiang, Zhu, Wenhuan, Liao, Chenghao, Dong, Xusheng, Liu, Xiaodong, Wei, Liangming, Hu, Nantao, He, Rong, Zhang, Yafei
• Format: Article
• Language: English
• Subjects: Carbon nanotubes; Intramolecular; P-i-n junction; Photovoltaic effect
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2016.12.048

Photovoltaic devices show promising applications in detection and energy fields as well as in next-generation optoelectronic circuits. The use of the ideal photosensitive material and device design are critical for achieving a high-performance photovoltaic device. Here, an intramolecular p-i-n junction photovoltaic device based on selectively doped carbon nanotubes is investigated. In this kind of device, the opposite ends of an individual single-walled carbon nanotube (SWCNT) channel are doped selectively by triethyloxonium hexachloroantimonate (OA) and polyethylene imine (PEI) to obtain stable p- and n- type SWCNT segments respectively, while the middle segment of the SWCNT is kept intrinsic, causing the formation of an intra-tube p-i-n junction for the efficient separation of photogenerated electron-hole pairs. The optical-absorption and electrical testing demonstrate that the OA and PEI can dope the SWCNTs into the stable p- and n- types, respectively. In the dark, the prepared p-i-n junction device behaves as a diode with a high rectification ratio >103 that can be tuned by the gate voltage. Under a 1550-nm monochromatic illumination, the device exhibits a good photovoltaic effect with a large open-circuit voltage of 0.41V and an external power conversion efficiency of ~4.2%. The quantum efficiency of the device is estimated to be as high as ~73%. [Display omitted] •A p-i-n junction photovoltaic device based on selectively doped CNTs is investigated.•It is demonstrated that the OA and PEI can dope SWCNTs into stable p- and n- type.•The devices behave as gate-dependent diodes, with a maximum rectification ratio >103.•The devices exhibit good photovoltaic effect with a Voc of 0.41V and a α of ~73%.