Resonant inelastic tunneling using multiple metallic quantum wells

• Published in: Nanophotonics (Berlin, Germany) Vol. 12; no. 16; pp. 3313 - 3321
• Main Authors: Zhang, Yiyun, Lepage, Dominic, Feng, Yiming, Zhao, Sihan, Chen, Hongsheng, Qian, Haoliang
• Format: Journal Article
• Language: English
• Published: Berlin De Gruyter 04.08.2023; Walter de Gruyter GmbH
• Subjects: Efficiency; Electron tunneling; Emissions control; Energy; inelastic electron tunneling; Interdisciplinary aspects; internal quantum efficiency; Laboratories; Light; Light sources; metallic quantum wells; Photon emission; photon-emission power; Photonics; Photons; Quantum efficiency; Quantum wells; Radiation; Resonant tunneling; Tunnels
• ISSN: 2192-8614; 2192-8606; 2192-8614
• DOI: 10.1515/nanoph-2023-0231

Tunnel nanojunctions based on inelastic electron tunneling (IET) have been heralded as a breakthrough for ultra-fast integrated light sources. However, the majority of electrons tend to tunnel through a junction elastically, resulting in weak photon-emission power and limited efficiency, which have hindered their practical applications to date. Resonant tunneling has been proposed as a way to alleviate this limitation, but photon-emissions under resonant tunneling conditions have remained unsatisfactory for practical IET-based light sources due to the inherent contradiction between high photon-emission efficiency and power. In this work, we introduce a novel approach that leverages much stronger resonant tunneling enhancement achieved by multiple metallic quantum wells, which has enabled the internal quantum efficiency to reach ∼1 and photon-emission power to reach ∼0.8 µW/µm . Furthermore, this method is applicable with different electronic lifetimes ranging from 10 fs to 100 fs simultaneously, bringing practical implementation of IET-based sources one step closer to reality.