Abstract

Single-photon emitters (SPEs) based on two-dimensional (2D) materials have attracted a lot of attention due to their unique benefits such as mechanical flexibility, high quantum yield, and easy integration on a chip. However, the electrical modulation of such emitters at a single-photon level still remains a challenge. Herein, we provide a new route to engineer electrically controllable purified SPEs in a monolayer (1L) WSe2 using a Si nanopyramid structure. The Si nanopyramid structures allow not only the generation of high strain to localize the SPEs but also the application of voltage for electrical modulation. Of particular interest, while our structure modulates the single-photon emission with an applied gate voltage, it does not exhibit unwanted spectral shift for the applied voltage, i.e., a negligible Stark effect, due to the existence of an air gap between the 1L-WSe2 and the nanopyramid. The single photon purity is improved by electrical modulation down to g(2)(0) = 0.06 ± 0.03.

Researchers at UNIST have developed a novel single-photon emitter (SPE) that can be electrically switched on and off with high purity and stability. This breakthrough addresses key challenges in quantum device engineering, paving the way for scalable quantum computing and secure quantum communication.

Based on a 2D semiconductor integrated with a silicon nanopyramid structure, the device generates single photons with minimal spectral shift during electrical modulation. By engineering a nanoscale air gap, the team effectively suppresses the Stark effect—preventing energy shifts in emitted photons—while maintaining a high level of single-photon purity (g(2)(0) ≈ 0.06). This design also reduces background emissions from defects, enhancing overall performance.

“This work represents a significant step toward integrated quantum photonics,” said the research team. “Controlling single photons electrically without spectral degradation opens new possibilities for scalable quantum devices.”

This study has been participated by Satyabrat Behera and Jong Sung Moon, as first authors of the study. Published in the March 2026 issue of Nano Letters, the research was supported by the IITP (Institute of Information & Communications Technology Planning & Evaluation)-ITRC (Information Technology Research Center) program by the Ministry of Science and ICT (MSIT), the National Research Foundation of Korea (NRF), and UNIST.

Journal Reference

Satyabrat Behera, Jong Sung Moon, Kirlie Iulius Figuera Michal, et al., "Electrical Control of Single Photon Emitters in WSe2 on a Si Nanopyramid Array with a Negligible Stark Effect," Nano Lett., (2026).