Vacuum Ultraviolet (120–200 nm) Avalanche Photodetectors

Abstract

Ultra‐sensitive photodetectors that can operate at vacuum ultraviolet (VUV) wavelengths are greatly needed in space exploration as well as photolithography sensing and imaging. Traditional photomultiplier tubes for weak VUV light detection have the characteristics of large physical volume and high working voltage, and thus, the development of ultra‐wide‐bandgap semiconductor‐based avalanche photodetectors (APD) with advantages of miniaturization, radiation resistance, and filter‐free characteristics is urgently needed. Here, this work reports the details and results of APDs prepared for VUV detection based on high‐quality AlN heterojunctions. An extremely low dark current of ≈30 fA is achieved, and appreciable spectral response in the range of 120–220 nm and a gain >4000 at room temperature are demonstrated for the first time. Such APDs with integrability are attractive for single‐photon detection and imaging at VUV wavelengths in the future.

Anisotropic photoresponse behavior of a LaAlO3 single-crystal-based vacuum-ultraviolet photodetector

“…A vacuum spectral response test system was used to obtain the spectral response (responsivity), including a miniature probe station placed in a vacuum chamber, a McPherson 302 monochromator, a 200 W deuterium lamp source L11798 (Hamamatsu), and a Keithley 6517B source meter. 42…”

Extremely High Photovoltage (3.16 V) Achieved in Vacuum-Ultraviolet-Oriented van der Waals Photovoltaics

“…The observation of 10–200 nm vacuum ultraviolet (VUV) spectroscopy is both an important approach for detecting solar activities like solar storms − and a direct tool used for studying the interaction of light with atoms, molecules, and condensed matter. − At present, optoelectronic devices applied in this band include photomultiplier tubes, Si diodes, and wide-bandgap semiconductor detectors, ,− which have become a research hotspot in this field owing to the advantages of miniaturization and high reliability with the problems of high power consumption and wide spectrum response faced by the former that need to be overcome . Aluminum nitride (AlN) with a wurtzite structure has a band gap of about 6.2 eV that corresponds well to the long wave edge (200 nm) of the VUV band, which endows it with a natural selective response to VUV light and thus makes AlN an ideal VUV detection material .…”

Ag2O/β-Ga2O3 Heterojunction-Based Self-Powered Solar Blind Photodetector with High Responsivity and Stability

“…For measuring and detecting UV light, wide band gap semiconductor materials, such as GaN, ZnO, and SiC, and some compound materials, such as Mg x Zn 1– x O, Al x Ga 1– x N, and Ga 2 O 3 (4.4–5.3 eV), have been used. − These materials have high radiation hardness and high chemical and thermal stabilities. However, the UV photodetector based on GaN, ZnO, and SiC cannot selectively respond to DUV light.…”