Flexible Broadband Graphene Photodetectors Enhanced by Plasmonic Cu3− xP Colloidal Nanocrystals

Tian Sun, Yongjie Wang, Wenzhi Yu, Yusheng Wang, Zhigao Dai, Zeke Liu, Bannur Nanjunda Shivananju, Yupeng Zhang, Kai Fu, Babar Shabbir, Wanli Ma, Shaojuan Li, Qiaoliang Bao

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26 Citations (Scopus)


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 (Cu3− xP) QDs is developed for efficient broadband photodetection. Unlike conventional PbS QDs that are toxic, Cu3− xP QDs are environmental friendly and have plasmonic resonant absorption in near-infrared (NIR) wavelength. The half-covered graphene with Cu3− xP 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 Cu3− xP NCs plays a key role in determining the charge transfer efficiency from Cu3− xP to graphene. The most efficient three-terminal photodetectors based on graphene-Cu3− xP exhibit broadband photoresponse from 400 to 1550 nm with an ultrahigh responsivity (1.59 × 105 A W−1) and high photoconductive gain (6.66 × 105) at visible wavelength (405 nm), and a good responsivity of 9.34 A W−1 at 1550 nm. The demonstration of flexible graphene-Cu3− xP photodetectors operated at NIR wavelengths may find potential applications in optical sensing, biological imaging, and wearable devices.

Original languageEnglish
Article number1701881
Number of pages9
Issue number42
Publication statusPublished - 13 Nov 2017


  • broadband
  • Cu P
  • flexibility
  • graphene
  • photodetector

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