All-Si Photodetectors with a Resonant Cavity for Near-Infrared Polarimetric Detection

Abstract

This work developed an all-Si photodetector with a surface plasmonic resonator formed by a sub-wavelength Au grating on the top of a Si-nanowire array and the same one beside the wires. The Au/Si interface with a Schottky barrier allows the photo-electron detection in near-infrared wavelength based on the internal emission of hot electrons generated by the surface plasmons in the cavity. Meanwhile, the Au sub-wavelength grating on the Si nanowire array acts as a polarizer for polarimetric detection. Finite-difference time-domain method was applied in the design of the novel device and state-of-art nanofabrication based on electron beam lithography was carried out. The characterization of the photo-electronic properties as well as the polarimetric detection demonstrate that the fabricated detectors on the silicon substrate possesses great prospects for sensing technology on all-Si.

Strain-engineered high-responsivity MoTe2 photodetector for silicon photonic integrated circuits

“…An integral device for photonic circuitry supporting a plethora of applications, such as sensing, data communication, and general signal processing is a monolithically integrated photodetector operating at near-infrared (NIR) [14][15][16][17]. The wavelength of 1550 nm is a prominent spectral choice since it a) overlaps with the gain spectrum of erbium-doped-fiber-amplifiers, and b) is transparent for foundry-based silicon photonics.…”

Generation of Hot Electrons with Chiral Metamaterial Perfect Absorbers: Giant Optical Chirality for Polarization-Sensitive Photochemistry

“…Therefore, hot electron generation can be used for applications in photodetection, − photochemistry, − and photovoltaics. , For a metal–semiconductor configuration, the high energy electrons generated from the nonradiative decay of surface plasmons in a metal can contribute to a detectable photocurrent when they overcome the Schottky barrier. This has been experimentally investigated in systems with both wide-gap and conventional semiconductors, such as Au–Al 2 O 3 , and Au–Si. ,, HEs are also favorable for photochemistry, since they can contribute to chemical reactions through an indirect energy transition occurring through the carrier injection from metal to molecular species. To date, tremendous research effort has been directed to the use of HEs for water splitting, − ,− H 2 dissociation, ,,, H 2 production from ethanol, ,, and CO 2 reduction. , However, the short relaxation times and relatively small populations of HEs excited in plasmonic materials hinder their application in photodetection and photocatalysis.…”

Nanoscale growth of a Sn-guided SiGeSn alloy on Si (111) substrates by molecular beam epitaxy

“…For instance, Si is an indirect bandgap semiconductor, and thus it is virtually impossible to realize a high-efficiency Si light source. 7,8 Moreover, because of the relatively large Si bandgap of 1.12 eV, the responsivity of Si-based photodetectors is extremely low for near-infrared wavelengths, 9,10 which is a significant obstacle to its application in the infrared optical communication field. In recent years, Ge has been identified as a promising material to achieve high-efficiency group IV infrared photodetectors [11][12][13][14][15][16][17][18] and light sources [19][20][21][22][23][24][25][26][27] , owing to its small bandgap (0.67 eV) and small energy difference (0.13 eV) between the Γ and L valleys (ΔEΓ-L).…”