Increased photocurrent in quantum dot infrared photodetector by subwavelength hole array in metal thin film

Abstract

Photocurrent enhancement in quantum dot (QD) infrared photodetector (QDIP) with an optical grating of subwavelength hole array in a thin metal film has been studied by calculating the transmission and diffraction of the infrared optical field through the grating and the light-matter interaction between the transmitted optical field and electrons confined in the QD. It is shown that due to the small aspect ratio of realistic QDs in QDIPs, the light diffraction due to the surface plasmon effect at the metal-semiconductor surface and the photonic subwavelength hole array structure is dominant in increasing the photocurrent.

Spectral selectivity of subwavelength gold-based photonic crystals on GaAs substrate

“…As these new technologies become more advanced and expensive, top-down approaches to improve current generation photodetectors have become of interest. Particularly the use of surface plasmonics in metallic photonic crystals for improving IR detector's performance has shown promising results [3]- [5]. In order to further investigate this option gold (Au)-based photonic crystal structures were fabricated on two substrates of Si and GaAs wafers, which is detailed in our previous work [4].…”

Emerging technologies for high performance infrared detectors

“…QDs as show in Figure 5, have zero dimensionality, have been incorporated into different material systems to enhance the efficiency and higher operating temperatures. Here we reviewed the two popular types of QDIPs based on III-V material (InGaAs/GaAs and InAs/InP) [64][65][66] and siliconbased material (Ge/Si) [67][68][69].…”

Leaky-mode effects in plasmonic-coupled quantum dot infrared photodetectors

“…Several groups have reported absorption enhancement of infrared (IR) detectors such as InAs quantum dot IR photodetectors (QDIPs) using surface plasma wave (SPW) coupling structures. [1][2][3][4][5][6] A metal film perforated with a 2dimensional (2D) hole array, referred to as a metal photonic crystal (MPC), often has been used as the plasmonic coupler. For the case of a homogenous semiconductor below an MPC of period p, the SPW wavelength excited at the MPC/semiconductor interface at normal incidence, k ij , and the SPW field penetration depth into the semiconductor, d ij , are given approximately by 3,7 k ij ffi p ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi…”

“…A reduction in coupling is critical in the applications of plasmonic couplers to semiconductor devices. Devices such as concentric gratings, 2 hole arrays, [3][4][5] and cor-rugated grooves 6 require different layer structures for fabrication and electrical/optical optimization, and are therefore very sensitive to SPW coupling. In this work, the variation with t of an MPC integrated on an n þ -doped top ohmic contact layer of an InAs QDIP is investigated.…”