Monolithic Interface Contact Engineering to Boost Optoelectronic Performances of 2D Semiconductor Photovoltaic Heterojunctions

Seunghoon Yang, Janghwan Cha, Jong Chan Kim, Donghun Lee, Woong Huh, Yoonseok Kim, Seong Won Lee, Hong Gyu Park, Hu Young Jeong, Suklyun Hong, Gwan Hyoung Lee, Chul Ho Lee

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

In optoelectronic devices based on two-dimensional (2D) semiconductor heterojunctions, the efficient charge transport of photogenerated carriers across the interface is a critical factor to determine the device performances. Here, we report an unexplored approach to boost the optoelectronic device performances of the WSe2-MoS2 p-n heterojunctions via the monolithic-oxidation-induced doping and resultant modulation of the interface band alignment. In the proposed device, the atomically thin WOx layer, which is directly formed by layer-by-layer oxidation of WSe2, is used as a charge transport layer for promoting hole extraction. The use of the ultrathin oxide layer significantly enhanced the photoresponsivity of the WSe2-MoS2 p-n junction devices, and the power conversion efficiency increased from 0.7 to 5.0%, maintaining the response time. The enhanced characteristics can be understood by the formation of the low Schottky barrier and favorable interface band alignment, as confirmed by band alignment analyses and first-principle calculations. Our work suggests a new route to achieve interface contact engineering in the heterostructures toward realizing high-performance 2D optoelectronics.

Original languageEnglish
Pages (from-to)2443-2451
Number of pages9
JournalNano Letters
Volume20
Issue number4
DOIs
Publication statusPublished - 2020 Apr 8

Keywords

  • 2D semiconductors
  • contact engineering
  • heterostructures
  • optoelectronics
  • photovoltaics
  • transition metal dichalcogenides

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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