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Flexible Broadband Graphene Photodetectors Enhanced by Plasmonic Cu 3− x P Colloidal Nanocrystals
Author(s) -
Sun Tian,
Wang Yongjie,
Yu Wenzhi,
Wang Yusheng,
Dai Zhigao,
Liu Zeke,
Shivananju Bannur Nanjunda,
Zhang Yupeng,
Fu Kai,
Shabbir Babar,
Ma Wanli,
Li Shaojuan,
Bao Qiaoliang
Publication year - 2017
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201701881
Subject(s) - photodetector , graphene , materials science , responsivity , photodetection , optoelectronics , quantum dot , plasmon , photoconductivity , absorption (acoustics) , nanocrystalline material , nanocrystal , monolayer , nanotechnology , composite material
The integration of graphene with colloidal quantum dots (QDs) that have tunable light absorption affords new opportunities for optoelectronic applications as such a hybrid system solves the problem of both quantity and mobility of photocarriers. In this work, a hybrid system comprising of monolayer graphene and self‐doped colloidal copper phosphide (Cu 3− x P) QDs is developed for efficient broadband photodetection. Unlike conventional PbS QDs that are toxic, Cu 3− x P QDs are environmental friendly and have plasmonic resonant absorption in near‐infrared (NIR) wavelength. The half‐covered graphene with Cu 3− x P nanocrystals (NCs) behaves as a self‐driven p–n junction and shows durable photoresponse in NIR range. A comparison experiment reveals that the surface ligand attached to Cu 3− x P NCs plays a key role in determining the charge transfer efficiency from Cu 3− x P to graphene. The most efficient three‐terminal photodetectors based on graphene‐Cu 3− x P exhibit broadband photoresponse from 400 to 1550 nm with an ultrahigh responsivity (1.59 × 10 5 A W −1 ) and high photoconductive gain (6.66 × 10 5 ) at visible wavelength (405 nm), and a good responsivity of 9.34 A W −1 at 1550 nm. The demonstration of flexible graphene‐Cu 3− x P photodetectors operated at NIR wavelengths may find potential applications in optical sensing, biological imaging, and wearable devices.