All-Oxide NiO/Ga₂O₃ p–n Junction for Self-Powered UV Photodetector

Abstract

Recently, Ga2O3-based self-powered ultraviolet photodetectors have aroused great interest due to their potential applications in civil, medical, and environmental monitoring fields. So far, most p–n junction photodetectors are fabricated with p-type semiconductors like GaN and SiC, which are usually nonoxide materials. As a result, the p-type semiconductors are oxidized and the conductive properties degenerated when constructing a p–n junction with the Ga2O3 thin film at a high growth temperature. In this work, we chose the oxide NiO as the p-type material and used radio-frequency reactive magnetron sputtering system to fabricate the all-oxide NiO/Ga2O3 p–n junction at room temperature and manufacture the self-powered UV photodetector. Thanks to the type II band alignment, the photodetector exhibits a responsivity (R) of 57 μA/W, a detectivity (D*) of 5.45 × 109 jones, and an I light/I dark ratio of 122 when exposed to a 254 nm light irradiation at 0 V. In addition, the photodetector based on the all-oxide NiO/Ga2O3 p–n junction shows good stability and reproducibility in air, oxygen, and vacuum. Our results provide an inexpensive and suitable pathway for the mass production of self-powered UV photodetectors.

A Flexible Self‐Powered UV Photodetector and Optical UV Filter Based on β‐Bi2O3/SnO2 Quantum Dots Schottky Heterojunction

“…It should be noted that β‐Bi 2 O 3 /SnO 2, being a self‐powered device, the responsivity and detectivity were obtained as 62.5 µA W −1 and 4.5 × 10 9 Jones respectively with UV light intensity of 7 µW cm −2 . Compared to the other self‐powered photodetectors, [ 33,34 ] the β‐Bi 2 O 3 /SnO 2 heterojunction device showed a good responsivity, detectivity, and limit of detection of 7 µW cm −2 . Further, annealing of the contacts were done at 70 °C and the responsivity values were recorded as shown in Figure S11, Supporting Information.…”

Self‐Powered Low‐Cost UVC Sensor Based on Organic‐Inorganic Heterojunction for Partial Discharge Detection

“…Photodiode type, however, is advantageous because it implements self-powered sensors at high response rates depending on the choice of materials. [3][4][5] Recently, solution-processed organic-inorganic p-n heterojunction photodiodes have emerged as a promising alternative to replace the various conventional Si-based (low bandgap that requires various additional band block filters) or III-V semiconductor-based (high bandgap that requires expensive highvacuum processes) photodiodes because of their light weight, simple fabrication process, inexpensiveness, and ease of largescale production. In particular, the low cost of device fabrication allows the installation of a number of devices in many different places in power facilities.…”

“…Photodiode type, however, is advantageous because it implements self‐powered sensors at high response rates depending on the choice of materials. [ 3–5 ]…”

Balancing the Transmittance and Carrier‐Collection Ability of Ag Nanowire Networks for High‐Performance Self‐Powered Ga2O3 Schottky Photodiode

“…[ 14 ] Since p‐type doping is rather difficult for Ga 2 O 3 , most self‐powered Ga 2 O 3 SBPDs are based on heterojunctions and Schottky junctions. Till now, the heterojunctions of Ga 2 O 3 with other WBG semiconductors (e.g., Nb:SrTiO 3 (NSTO), [ 5 ] ZnO, [ 14,18–21 ] GaN, [ 15,22 ] CuSCN, [ 23 ] diamond, [ 24 ] 4H‐SiC, [ 25 ] NiO, [ 26,27 ] γ‐CuI, [ 28 ] and CuMO 2 (M = Ga 3+ , Cr 3+ ), [ 29 ] ) organic conductive polymers (e.g., poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate, or PEDOT:PSS), [ 17,30–32 ] 2D materials (e.g., MoS 2 ), [ 33 ] and Si, [ 34 ] have been utilized in self‐powered SBPDs. Although much impressive progress has been achieved, heterojunction‐based Ga 2 O 3 device is hindered by several limitations, including extra interface states induced by lattice mismatch, [ 30 ] carrier blocking from imperfect band alignment, [ 20 ] nonsolar‐blind response due to the small bandgap of the foreign substrate, [ 35 ] and complicated fabrication process.…”