Ultrafast Hot-Carrier Photovoltaics of Type-I Monolayer Heterojunctions in the Broad Spectral Ranges

Ji Ho Sung, Soonyoung Cha, Hoseok Heo, Sangwan Sim, Juho Kim, Hyunyong Choi, Moon Ho Jo

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Strong interlayer photoresponses in monolayer (ML) semiconductor stacks, such as substantial light absorption and charge separation across interlayer band alignments, suggest potentials for two-dimensional photovoltaics (PVs). Here, we report an interlayer PV conversion in a type-I ML heterojunction by ultrafast interlayer transfer of photoexcited hot carriers in the broad spectral ranges. Specifically, low-energy photoexcitation on a stack of a narrow-band-gap (Eg) Bi2Te3 few-layer and a large-Eg MoS2 ML permits interlayer transfer of transient hot carriers from the Bi2Te3 layer to the excitonic states of the neighboring MoS2 ML within a time scale of ∼70 fs, producing interlayer charge separation. Thereby we achieve substantial conversion efficiency from a MoS2 ML with visible to infrared light illumination.

Original languageEnglish
Pages (from-to)429-434
Number of pages6
JournalACS Photonics
Volume4
Issue number3
DOIs
Publication statusPublished - 2017 Mar 15

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

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