Plasmonically-enhanced mid-infrared photoluminescence in a metal/narrow-gap semiconductor structure

¹ Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University Hangzhou, Zhejiang 310027, PRC
² Department of Information and Electronic Engineering, Zhejiang University City College Hangzhou, Zhejiang 310015, PRC
³ Department of Physics, Zhejiang Normal University - Jinhua, Zhejiang 312001, PRC

^(a) hzwu@zju.edu.cn (corresponding author)

Received: 23 December 2015
Accepted: 9 May 2016

Abstract

We report the enhancement of the mid-infrared (MIR) luminescence intensity in a nanoscale metal/semiconductor structure by the coupling of surface plasmon polaritons (SPPs) with excitons in a narrow-gap semiconductor. The SPPs are efficiently excited by the total internal reflection photons at a metal/semiconductor interface. The intense electric field induced by SPPs, in turn, greatly changes the radiative recombination rates of the excitons generated by the pumping laser and thus the MIR luminescence intensity. The finding avails the understanding of fundamental science of SPs in narrow-gap semiconductors and the development of novel MIR devices.