A Tunneling Light-Emitting Device With Ultra-Narrow Linewidth Emission at Room-Temperature

Light-emitting devices with ultra-narrow linewidth have important applications in high-precision measurements and emerging quantum technologies. Charge carriers in solid-state matrix often suffer from interactions with phonons, spin noise and drifting electric fields, which results in spectral diffusion and additional phase noise. Here we report an ultra-narrow linewidth ( $\sim 76 \; \mu $ eV) electroluminescence from molecular nitrogen species in the ambience at room temperature. Through detailed numerical calculation and experimental analysis, we show that the second positive system of nitrogen species can be excited by tunneling electrons field-emitted from a metal-insulator-semiconductor heterostructure on commercially available Si and GaN substrates. The tunneling light-emitting devices (TLED) feature an excellent scalability and devices with minimal lateral dimension of $5 \; \mu $ m have been demonstrated. This work sheds light on the integration of atomic, molecular, and optical physics with the solid-state platform as well as novel quantum optoelectronics.