Plasmonic Near-Infrared Photoconductor Based on Hot Hole Collection in the Metal-Semiconductor-Metal Junction

Abstract

Harvesting energetic carriers from plasmonic resonance has been a hot topic in the field of photodetection in the last decade. By interfacing a plasmonic metal with a semiconductor, the photoelectric conversion mechanism, based on hot carrier emission, is capable of overcoming the band gap limitation imposed by the band−to−band transition of the semiconductor. To date, most of the existing studies focus on plasmonic structural engineering in a single metal–semiconductor (MS) junction system and their responsivities are still quite low in comparison to conventional semiconductor, material−based photodetection platforms. Herein, we propose a new architecture of metal−semiconductor–metal (MSM) junctions on a silicon platform to achieve efficient hot hole collection at infrared wavelengths with a photoconductance gain mechanism. The coplanar interdigitated MSM electrode’s configuration forms a back−to−back Schottky diode and acts simultaneously as the plasmonic absorber/emitter, relying on the hot−spots enriched on the random Au/Si nanoholes structure. The hot hole−mediated photoelectric response was extended far beyond the cut−off wavelength of the silicon. The proposed MSM device with an interdigitated electrode design yields a very high photoconductive gain, leading to a photocurrent responsivity up to several A/W, which is found to be at least 1000 times higher than that of the existing hot carrier based photodetection strategies.

In situ photoelectric biosensing based on ultranarrowband near-infrared plasmonic hot electron photodetection

“…In previous works, Au/Si Schottky PDs demonstrated a broad operating wavelength range from 400 to 2000 nm. [27][28][29] On the other hand, wavelengthdependent photodetection is achieved by SPR-modulated light absorption. Although plasmonic antennas, Tamm state, and metasurfaces have been used to tune the photoelectric response, [34][35][36] spectrally selective photodetection was realized in a relatively broad band down to 30 nm with a normalized response bandwidth well above 3%.…”

“…On the one hand, a Schottky junction is formed at the Au/Si interface and the ohmic electrode is formed at the back side of the Si substrate. As a result, interband transition in Si dominates the photoelectric response under illumination with a wavelength smaller than 1100 nm, while the photogenerated HEs, 27 – 33 as shown in Fig. 1(b), become the main contribution factor for the subbandgap photodetection of Si.…”

“…1(b), become the main contribution factor for the subbandgap photodetection of Si. In previous works, Au/Si Schottky PDs demonstrated a broad operating wavelength range from 400 to 2000 nm 27 – 29 On the other hand, wavelength-dependent photodetection is achieved by SPR-modulated light absorption.…”

Study of Metal–Graphene Aerogel for Efficient Solar Energy Interface Evaporation Based on One‐Step Thermal Reduction Method

“…In general, there are several categories of photothermal materials: precious metal nanoparticle materials [ 15 ] (gold, silver, copper, platinum, and cobalt, etc. ); metal–semiconductor materials [ 16 ] (PB @ CF nanocrystals, Ti 2 O 3 , Cu 7 S 4 , MoO 3 , and Al 2 O 3 , etc. ); polymer materials [ 17 ] (polypyrrole, polydopamine, etc.…”