Highly-efficient electrically-driven localized surface plasmon source enabled by resonant inelastic electron tunneling

Haoliang Qian; Shilong Li; Su-Wen Hsu; Ching-Fu Chen; Fanglin Tian; Andrea R Tao; Zhaowei Liu

doi:10.1038/s41467-021-23512-2

Highly-efficient electrically-driven localized surface plasmon source enabled by resonant inelastic electron tunneling

Nat Commun. 2021 May 25;12(1):3111. doi: 10.1038/s41467-021-23512-2.

Authors

Haoliang Qian^#^{1

2}, Shilong Li^#¹, Su-Wen Hsu^#³, Ching-Fu Chen¹, Fanglin Tian¹, Andrea R Tao^{3

4}, Zhaowei Liu^{5

6

7}

Affiliations

¹ Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, USA.
² Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China.
³ Department of NanoEngineering, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, USA.
⁴ Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, USA.
⁵ Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, USA. zhaowei@ucsd.edu.
⁶ Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, USA. zhaowei@ucsd.edu.
⁷ Center for Memory and Recording Research, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, USA. zhaowei@ucsd.edu.

^# Contributed equally.

Abstract

On-chip plasmonic circuitry offers a promising route to meet the ever-increasing requirement for device density and data bandwidth in information processing. As the key building block, electrically-driven nanoscale plasmonic sources such as nanoLEDs, nanolasers, and nanojunctions have attracted intense interest in recent years. Among them, surface plasmon (SP) sources based on inelastic electron tunneling (IET) have been demonstrated as an appealing candidate owing to the ultrafast quantum-mechanical tunneling response and great tunability. However, the major barrier to the demonstrated IET-based SP sources is their low SP excitation efficiency due to the fact that elastic tunneling of electrons is much more efficient than inelastic tunneling. Here, we remove this barrier by introducing resonant inelastic electron tunneling (RIET)-follow a recent theoretical proposal-at the visible/near-infrared (NIR) frequencies and demonstrate highly-efficient electrically-driven SP sources. In our system, RIET is supported by a TiN/Al₂O₃ metallic quantum well (MQW) heterostructure, while monocrystalline silver nanorods (AgNRs) were used for the SP generation (localized surface plasmons (LSPs)). In principle, this RIET approach can push the external quantum efficiency (EQE) close to unity, opening up a new era of SP sources for not only high-performance plasmonic circuitry, but also advanced optical sensing applications.