Tunable directional emission from electrically driven nano-strip metal–insulator–metal tunnel junctions

Kishen, Saurabh and Tapar, Jinal and Emani, Naresh Kumar (2022) Tunable directional emission from electrically driven nano-strip metal–insulator–metal tunnel junctions. Nanoscale Advances. pp. 1-8. ISSN 2516-0230

Text
NANOSCALE_ADVANCES.pdf - Published Version
Restricted to Registered users only
Download (783kB) | Request a copy

Abstract

Electrically driven nanoantennas for on-chip generation and manipulation of light have attracted significant attention in recent times. Metal-insulator-metal (MIM) tunnel junctions have been extensively used to electrically excite surface plasmons and photons via inelastic electron tunneling. However, the dynamic switching of light from MIM junctions into spatially separate channels has not been shown. Here, we numerically demonstrate switchable, highly directional light emission from electrically driven nano-strip Ag-SiO2-Ag tunnel junctions. The top electrode of our Ag-SiO2-Ag stack is divided into 16 nano-strips, with two of the tunnel junctions at the centre (S-L and S-R) acting as sources. Using full-wave electromagnetic simulations, we show that when S-L is excited, the emission is highly directional with an angle of emission of -30 degrees and an angular spread of similar to 11 degrees. When the excitation is switched to S-R, the emission is redirected to an angle of 30 degrees with an identical angular spread. A directivity of 29.4 is achieved in the forward direction, with a forward-to-backward ratio of 12. We also demonstrate wavelength-selective directional switching by changing the width, and thereby the resonance wavelength, of the sources. The emission can be tuned by varying the periodicity of the structure, paving the way for electrically driven, reconfigurable light sources.

[error in script]

IITH Creators:

IITH Creators	ORCiD
Emani, Naresh Kumar	https://orcid.org/0000-0002-0488-921X

Item Type:

Article

Additional Information:

This work is supported by Science and Engineering Research Board (ECR/2018/002452, SB/S2/RJN-007/2017) and Ministry of Education (STARS/APR2019/NS/774). S. K. and J. T. acknowledge the Ministry of Education (MOE), Government of India, for the research fellowship to undertake their PhD studies.

Uncontrolled Keywords:

LIGHT-EMISSION,NANOPHOTONICS,SCATTERING

Subjects:

Electrical Engineering

Divisions:

Department of Electrical Engineering

Depositing User:

. LibTrainee 2021

Date Deposited:

16 Aug 2022 10:10

Last Modified:

16 Aug 2022 10:10