Confinement of excited states in two-dimensional, in-plane, quantum heterostructures

Gwangwoo Kim, Benjamin Huet, Christopher E. Stevens, Kiyoung Jo, Jeng Yuan Tsai, Saiphaneendra Bachu, Meghan Leger, Seunguk Song, Mahfujur Rahaman, Kyung Yeol Ma, Nicholas R. Glavin, Hyeon Suk Shin, Nasim Alem, Qimin Yan, Joshua R. Hendrickson, Joan M. Redwing, Deep Jariwala

Research output: Contribution to journalArticlepeer-review

Abstract

Two-dimensional (2D) semiconductors are promising candidates for optoelectronic application and quantum information processes due to their inherent out-of-plane 2D confinement. In addition, they offer the possibility of achieving low-dimensional in-plane exciton confinement, similar to zero-dimensional quantum dots, with intriguing optical and electronic properties via strain or composition engineering. However, realizing such laterally confined 2D monolayers and systematically controlling size-dependent optical properties remain significant challenges. Here, we report the observation of lateral confinement of excitons in epitaxially grown in-plane MoSe2 quantum dots (~15-60 nm wide) inside a continuous matrix of WSe2 monolayer film via a sequential epitaxial growth process. Various optical spectroscopy techniques reveal the size-dependent exciton confinement in the MoSe2 monolayer quantum dots with exciton blue shift (12-40 meV) at a low temperature as compared to continuous monolayer MoSe2. Finally, single-photon emission (g2(0) ~ 0.4) was also observed from the smallest dots at 1.6 K. Our study opens the door to compositionally engineered, tunable, in-plane quantum light sources in 2D semiconductors.

Original languageEnglish (US)
Article number6361
JournalNature communications
Volume15
Issue number1
DOIs
StatePublished - Dec 2024

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • General Biochemistry, Genetics and Molecular Biology
  • General Physics and Astronomy

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