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

Research output: Contribution to journalArticleResearchpeer-review

26 Citations (Scopus)

Abstract

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
JournalSmall
Volume13
Issue number42
DOIs
Publication statusPublished - 13 Nov 2017

Keywords

  • broadband
  • Cu P
  • flexibility
  • graphene
  • photodetector

Cite this