Effect of Oxygen Plasma on β-Ga₂O₃ Deep Ultraviolet Photodetectors Fabricated by Plasma-Assisted Pulsed Laser Deposition

Abstract

We fabricated metal–semiconductor–metal-structured β-Ga2O3 photodetectors using a plasma-assisted pulsed laser deposition system with various oxygen plasma radio frequency (RF) powers ranging from 0 to 100 W. All optoelectronic properties of the material were enhanced as the RF power increased. β-Ga2O3 photodetector with RF power of 100 W showed the best optoelectronic characteristics, such as photoresponsivity of 0.39 A/W, external quantum efficiency of 192.61%, and detectivity of 9.09 × 1013 cm Hz1/2/W. In addition, photo-switching analysis revealed the fastest photoresponse speeds (1.46 and 0.21 s) for on/off switching. These results originate from the decrease in the oxygen vacancy defect concentration in the β-Ga2O3 films by the oxygen RF power. Our results suggest that β-Ga2O3 photodetectors fabricated with oxygen plasma can optimize and improve the photodetection performance and can be applied for future deep ultraviolet detectors.

Self-assembled metal-oxo clusters for sensitive and low-powered ultraviolet photodetectors

“…3c compares the SCLC-derived trap density and bandgap values of the ZOCs and benchmark UV-sensitive materials. The trap densities of ZOCs are significantly lower than those of wide-bandgap metal oxides and metal nitrides (such as ZnO, Ga 2 O 3 , TiO 2 , and GaN) and comparable to those of organic/inorganic narrow-bandgap perovskites (such as Cs-FAPbI 3 , MAPbI 3 , FAMACs, and (FAPbI 3 ) 0.97 (MAPbBr 3 ) 0.03 ), 1,28–46 suggesting that the as-prepared ZOCs can serve as promising UV photoactive materials that exhibit both high UV selectivity and efficient photon-induced charge collection. Moreover, the trap density of ZOC@PEI was significantly higher than that of ZOC, implying that the ZOC/PEI interfaces can act as electron-trapping sites.…”

High-Performance Solar-Blind Photodetector Based on (010)-Plane β-Ga2O3 Thermally Oxidized from Nonpolar (110)-Plane GaN

“…Here, a biexponential equation is used to fit the rise and decay processes, as shown in Figure b I = I 0 + A normale − t / τ 1 + B normale − t / τ 2 where I 0 is the steady state of I photo , A and B are the constants, and τ 1 and τ 2 represent the relaxation time constants. In general, the fast component τ 1 is related to the band-to-band transition, while the slow component τ 2 is attributed to the charge carrier trapping/detrapping influenced by intrinsic defects, the so-called persistent photoconductivity. , The fitted fast and slow components for the rise process (τ r1 and τ r2 ) and decay process (τ d1 and τ d2 ) are summarized in Table . As a result of the relatively high crystalline quality of (010)-plane β-Ga 2 O 3 , the fast components τ r1 and τ d1 of the SBPD fabricated in this study are only 0.238 and 0.062 s, respectively, and the slow components τ r2 and τ d2 are 6.438 and 2.650 s, respectively.…”

“…These parameters at 5 V for the SBPDs fabricated in this work and the previously reported results are summarized in Table 1. It is clear that the Meanwhile, D, a parameter that describes the ability to detect weak optical signals, 44 reaches 2.39 × 10 12 Jones. Both PDCR and D are considered to be at a high level in the state of the art.…”

“…where I 0 is steady state of I photo , A and B are the constants, and τ 1 and τ 2 represent the relaxation time constants. In general, the fast component τ 1 is related to the band-to-band transition, 44 while the slow component τ 2 is attributed to the charge carrier trapping/detrapping influenced by intrinsic defects, the so-called persistent photoconductivity. 44,48 The fitted fast and slow components for the rise process (τ r1 and τ r2 ) and decay process (τ d1 and τ d2 ) are summarized in Table 2.…”

“…A PDCR up to 2.95 × 10 6 is achieved as a result of the high I photo and low I dark , indicating that the (010)-plane β-Ga 2 O 3 -based SBPD fabricated in this study has a relatively high sensitivity. Meanwhile, D , a parameter that describes the ability to detect weak optical signals, reaches 2.39 × 10 12 Jones. Both PDCR and D are considered to be at a high level in the state of the art.…”