High-Performance Solar Blind Ultraviolet Photodetector Based on Single Crystal Orientation Mg-Alloyed Ga₂O₃ Film Grown by a Nonequilibrium MOCVD Scheme

Abstract

It is crucial to realize high photoresponsivity and a fast response speed to meet the application requirements of solar blind ultraviolet (SBUV) photodetectors (PDs) in wireless communication, fire warning, and other fields. Such high-performance PDs depend on high-quality films. In this paper, a nonequilibrium MOCVD growth scheme is reported to obtain Mg-alloyed Ga2O3 films with single crystal orientation. On the basis of this film, the fabricated PD exhibits a large on/off ratio of approximately 105 (I 254 nm light/I dark), ultrahigh external quantum efficiency of 4341%, and high photoresponsivity of 8.9 A/W under 3 V bias. The performance of this device is greatly enhanced compared to the performances of those PDs based on amorphous gallium oxide films previously reported, which is attributed to the fewer number of grain boundaries of the single crystal orientation Ga2O3 films. Furthermore, it is found that under the same growth conditions, Ga2O3 films doped with an appropriate amount of acceptor impurity Mg possess less oxygen vacancies and better crystal quality, compared with unalloyed Ga2O3 films. The characterizations indicate that the Mg-alloyed Ga2O3 films with single crystal orientation grown by the nonequilibrium MOCVD scheme are feasible for preparing high-performance SBUV PDs.

A Strategic Review on Gallium Oxide Based Deep‐Ultraviolet Photodetectors: Recent Progress and Future Prospects

“…Ma et al. [ 165 ] have found that under the same growth conditions, doping of gallium oxide thin films with appropriate amount of an acceptor like Mg, leads to better crystal quality and less oxygen vacancies as compared to the unalloyed Ga 2 O 3 films (Figure 7d–f). Bandgap of gallium oxide can be tuned easily by incorporating either Nitrogen [ 182 ] or Indium.…”

“…d-f) Structure and performance of Mg-alloyed PD showing an enhanced performance. d-f) Reproduced with permission [165]. Copyright 2019, American Chemical Society.…”

Chemical composition tuning induced variable and enhanced dielectric properties of polycrystalline Ga2‐2xWxO3 ceramics

“…[1][2][3][4][5][6][7][8][9] Gallium oxide (Ga 2 O 3 ) has stood out of the transparent, wide band gap oxides and there have been demonstrated applications which utilizes its unique characteristics. 5,[10][11][12][13][14] Among the known polymorphs of Ga 2 O 3 viz. -, -, -, -, -, [15][16][17] -Ga 2 O 3 is the most stable.…”

“…14,18 The electrical breakdown voltage is exceptionally high 8 MV/cm, which in comparison to SiC and GaN, 2.5 and 3.3 MV/cm, respectively, is in multiples. 13,19,20 These properties make -Ga 2 O 3 a suitable candidate for a wide variety of energy, electronic, power, optoelectronics, and catalysis applications, which include solar blind UV-photodetectors, 5,12,14,21 light emitting diodes (LEDs) , 22,23 transparent conducting oxide electrodes (TCOs) , 24,25 photo-and electro-catalysts, [26][27][28] high-temperature sensors, 29,30 high power electronic devices [11][12][13][14]31,32 with a potential to dwarf the existing SiN, Si and GaN devices in terms of performance. On the other hand, the potential for Ga 2 O 3 to derive new properties and phenomena, which can facilitate designing materials especially for energy related applications, is continually evolving.…”

“…Oxide dielectrics and semiconductors have been at the center of technological applications in photocatalysis, chemical sensing, energy storage, and optoelectronics for decades 1‐9 . Gallium oxide (Ga 2 O 3 ) has stood out of the transparent, wide band gap oxides and there have been demonstrated applications which utilizes its unique characteristics 5,10‐14 . Among the known polymorphs of Ga 2 O 3 viz.…”