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Monolayer two-dimensional transition metal dichalcogenides offer strong excitonic responses and gate-tunable optical properties, making them attractive for next-generation photonic and optoelectronic devices. However, achieving wafer-scale, room-temperature operation with a high photoluminescence modulation depth remains a key challenge owing to the limited electrostatic control and inefficient light–matter coupling. To address this challenge, an international research team led by Dr. Yu-Jung Lu at the Research Center of Applied Sciences, Academia Sinica, in collaboration with Prof. Vincent Tung’s team at the University of Tokyo, has successfully integrated large-area monolayer molybdenum disulfide (MoS2), a two-dimensional semiconductor, with an atomically smooth hafnium nitride plasmonic back-gate electrode. This work establishes a new active tunable light-emitting platform for two-dimensional materials that operates at room temperature.

Over the past few years, Dr. Lu’s laboratory has found that hafnium nitride offers high electrical conductivity, tunable work function, and plasmonic properties. When used as a back-gate electrode, it helps charges accumulate at the interface of two-dimensional semiconductor/gate dielectric, and promotes the formation of trions. Trions are charged quasiparticles that play an important role in controlling the gate-tunable light emission of two-dimensional materials. By applying a gate voltage, the device achieves a light-emission modulation strength five times higher than that of conventional silicon-gated devices, while maintaining stable room-temperature operation.

This breakthrough overcomes long-standing challenges in chip-scale fabrication and efficient gate-tunable emission control of two-dimensional materials. The results demonstrate a scalable, low-power, and CMOS-compatible approach for realizing actively reconfigurable two-dimensional light sources. This platform may enable future applications in on-chip integrated photonics, visible light communication, tunable light-emitting devices, and advanced control of light–matter interactions in two-dimensional systems. The research has been published on May 25, 2026 in Nature Photonics. The research was supported by Academia Sinica, the National Science and Technology Council, and the Japan Science and Technology Agency (ASPIRE).