Synthesis of ultrathin composition graded doped Lateral WSe2/WS2 heterostructures

Zhipeng Li, Jialu Zheng, Yupeng Zhang, Changxi Zheng, Wei-Yen Woon, Min-Chiang Chuang, Hung-Chieh Tsai, Chia-Hao Chen, Asher Davis, Zai-Quan Xu, Jiao Lin, Han Zhang, Qiaoliang Bao

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11 Citations (Scopus)

Abstract

Lateral transition-metal dichalcogenide and their heterostructures have attracted substantial attention, but there lacks a simple approach to produce large-scaled optoelectronic devices with graded composition. In particular, the incorporation of substitution and doping into heterostructure formation is rarely reported. Here, we demonstrate growth of a composition graded doped lateral WSe2/WS2 heterostructure by ambient pressure chemical vapor deposition in a single heat cycle. Through Raman and photoluminescence spectroscopy, we demonstrate that the monolayer heterostructure exhibits a clear interface between two domains and a graded composition distribution in each domain. The coexistence of two distinct doping modes, i.e., interstitial and substitutional doping, was verified experimentally. A distinct three-stage growth mechanism consisting of nucleation, epitaxial growth, and substitution was proposed. Electrical transport measurements reveal that this lateral heterostructure has representative characteristics of a photodiodes. The optoelectronic device based on the lateral WSe2/WS2 heterostructure shows improved photodetection performance in terms of a reasonable responsivity and a large photoactive area.

Original languageEnglish
Pages (from-to)34204-34212
Number of pages9
JournalACS Applied Materials & Interfaces
Volume9
Issue number39
DOIs
Publication statusPublished - 2017

Keywords

  • Chemical vapor deposition
  • Heterostructure
  • Optoelectronic devices
  • Substitution
  • Transition-metal dichalcogenides
  • Two-dimensional material

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