A self-powered and broadband UV PIN photodiode employing a NiOx layer and a β-Ga₂O₃ heterojunction

Abstract

Crucial commercial and space applications require the detection of broadband ultraviolet (UV) rays spanning from UV-A to UV-C. In this study, the authors demonstrate a broadband UV photodetector employing a p-type NiOx layer and an n-type β-Ga2O3 heterostructure in PIN configuration for the first time. Simulations are conducted to optimize the doping concentration and thickness of the NiOx layer, ensuring that (a) a reasonable depletion width is maintained within the NiOx layer for UV-A and UV-B light absorption; (b) anode ohmic contacts are formed on the nondepleted NiOx film, and (c) >70% of the UV-C light is absorbed by β-Ga2O3. The optimized NiOx/ β-Ga2O3 PIN photodiode exhibits good responsivity to incident light wavelengths in the UV-A, UV-B, and UV-C regions. While the NiOx layer is considered to be responsible for providing good photoresponsivity in the UV-A and UV-B regions, a highly resistive (near-intrinsic) β-Ga2O3 layer is required for the absorption of incident UV-C light. A record detectivity of >1011 cmHz0.5W−1 for the UV-B and UV-C regions and >1010 cmHz0.5W−1 for the UV-A region is observed in the NiOx/ β-Ga2O3 heterostructure PIN photodiode during the self-powered operation. The results presented in this study are promising and instigate device design strategies for (ultra)wide bandgap semiconductor-based broadband UV PIN photodetectors.

Influence of Energetic Particles and Electron Injection on Minority Carrier Transport Properties in Gallium Oxide

“…Figure 20), and is determined by the band alignment between the two materials, as reported previously in Ref. [78]. Under forward bias, the depletion layer of the p-n junction is collapsed, and holes diffuse into the Ga2O3.…”

Globalization in Photonics Research and Development

“…Related to photonics research, Professor Xiaohang Li's Advanced Semiconductor Laboratory [https://cemse.kaust.edu.sa/semiconductor] focused on the formation of ultrawide bandgap semiconductor for ultraviolet optoelectronic devices, notably in group-III-nitrides and group-III-oxides deep ultraviolet light-emitters [126], boron-containing nitrides [127], and Ga2O3 membrane [128]. The team has also reported > REPLACE THIS LINE WITH YOUR MANUSCRIPT ID NUMBER (DOUBLE-CLICK HERE TO EDIT) < significant work in semiconductor heterostructures design and deep-ultraviolet photodetectors [129], [130].…”

On band-to-band tunneling and field management in NiOx/β-Ga2O3 PN junction and PiN diodes

“…Unfortunately, realizing p-type β-Ga 2 O 3 is a significant challenge for numerous reasons [12]. Meanwhile, p-type NiO x has emerged as a potential candidate to complement the n-type β-Ga 2 O 3 films [13]. Consequently, NiO x /β-Ga 2 O 3 heterojunction based diodes exceeding kilovolts of breakdown voltage and amps of ON current have been recently demonstrated [14][15][16][17][18].…”