β-Ga₂O₃ has become an ultimate choice of emerging new-generation material for its wide range of compelling applications in power electronics. In this review, we have explored the available radiations in the atmosphere and the effects of radiation on the β-Ga₂O₃ material and devices. The focus in this review summarizes various studies covering different radiation such as swift heavy ions, protons, neutrons, electrons, Gamma, and X-rays to understand the radiation-induced effects on the structure and their reliable performance in harsh environments. In addition, we focused on the various pre-existing defects in β-Ga₂O₃ and the emergence of radiation-induced defects that provoke a severe concern, especially from the device performance point of view. This review presents the irradiation-induced effects on the devices such as high-power devices such as Schottky barrier diodes (SBDs), field-effect transistors (FETs), metal-oxide-semiconductor (MOS) devices, and photodetectors. Some key studies including the changes in carrier concentration with a removal rate, Schottky barrier height (SBH), ideality factor, defect dynamics dielectric damage, interface charge trapping, a thermally activated recovery mechanism for charge carriers at elevated temperature, and diffusion length of minority charge carriers. These reports show that β-Ga₂O₃-based devices could be deployable for space or high-radiation terrestrial applications. These results provide/suggest a better device design based on the radiation degradation studies in the state-of-the-art β-Ga₂O₃ devices.

The electrical device characteristics of Ni/β-Ga₂O₃ vertical Schottky barrier diodes (SBDs) were measured in situ during the irradiation of 120 MeV Ag⁷⁺ swift heavy ions (SHIs). These devices exhibit SHI irradiation-induced degradation with 120 MeV Ag⁷⁺ ions in the ion fluence ranges of 1 × 10¹⁰ to 1 × 10¹² ions/cm². The height of the Schottky barrier is found to decrease from 1.11 to 0.93 eV, and the ideality factor increases from 1.16 to 2.06. These changes indicate the degradation of the device with SHI irradiation. A significant four orders increase is observed in the leakage current density from 4.04 × 10⁻⁸ to 1.98 × 10⁻⁴ A/cm² at −1 V, and the series resistance also increases from 3.38 × 10³ to 1.15 × 10⁴ Ω. X-ray photoelectron spectroscopy measurements show that the Ga ions are present in divalent and trivalent states with the spectral features having the binding energies centered at 20.2 eV and 19.9 eV (Ga 3d core-levels) before and after ion irradiation. The O 2s peak shifts to 23.7 eV, and there is an increase in intensity and peak broadening due to the change in the trivalent to divalent state of Ga due to the irradiation. The O(I) peak appears at 530.7 eV in the pristine sample with the Ga–O bonding with the Ga³⁺ state in pure Ga₂O₃. Moreover, there is a significant change in the intensity and the peak width of O(II) centered at 533.0 eV after ion irradiation at the fluence of 1 × 10¹² ions/cm². This indicates that there is an increase in the surface adsorbed/lattice oxygen, resulting in GaO.

β -Ga ₂ O ₃ is an interesting new generation wide bandgap semiconductor for power device applications. The gamma irradiation was performed on the HfO ₂ / β -Ga ₂ O ₃ -based metal-oxide-semiconductor capacitors at 1 kGy and 200 kGy doses. The leakage current density variation at −1 V is 3.47 × 10 ⁻⁷ A cm ⁻² , 5.90 × 10 ⁻⁷ A cm ⁻² and 4.91 × 10 ⁻⁶ A cm ⁻² for the pristine, 1 kGy and 200 kGy devices, respectively. In the case of substrate injection, the Schottky emission mechanism appears to be dominant in the 0.65 to 2.0 MV cm ⁻¹ electric field range. The barrier heights (Ni/HfO ₂ / β -Ga ₂ O ₃ ) 0.95 eV, 0.86 eV and 0.83 eV were extracted from Schottky emission for the pristine, 1 kGy and 200 kGy doses, respectively. However, as the dose increases to 200 kGy, the charge-trapping favors the trap-assisted Poole–Frenkel (PF) tunneling mechanism. In this case, the PF emission mechanism seems to be dominant for the pristine and 1 kGy in the range of 2.0–4.0 MV cm ⁻¹ , whereas for 200 kGy it is 1.45 to 4.0 MV cm ⁻¹ which indicates that the defect assisted PF tunneling is predominant at 200 kGy irradiation dose. There is an increase in the density of oxide traps ( D _ot ) changes from 1.14 × 10 ¹² cm ⁻² eV ⁻¹ to 1.47 × 10 ¹² cm ⁻² eV ⁻¹ , and the density of interface traps has increased from 1.95 × 10 ¹¹ cm ⁻² eV ⁻¹ to 3.80 × 10 ¹¹ cm ⁻² eV ⁻¹ for the pristine and 200 kGy samples, respectively. The peaks of Photoluminescence show that the three bands of defects centered at 3.0, 2.7 and 2.2 eV. These peaks have possibly arisen from the vacancies of oxygen. At 200 kGy high dose, the defect band emissions were found at 2.9, 2.6 eV and a broad emission at 2.1 eV indicates the increase in the denisty of oxide-trapped charges within the HfO ₂ layer.

In situ ${I}$ – ${V}$ and ${C}$ – ${V}$ measurements were performed on Pt/PtOx/ $\beta $ -Ga2O3 vertical Schottky barrier diodes (SBD) during 120 MeV Au9+ swift heavy ion (SHI) irradiation in a fluence range of $1\times 10^{{10}}$ – $2\times 10^{{12}}$ ions/cm2. The reverse leakage current density increased from $1.21\times 10^{-{10}}$ to $1.69\times 10^{-{4}}$ A/cm2 at −1 V. The Schottky barrier height (SBH) remains close to ~1.8 eV up to the fluence of $5\times 10^{{11}}$ ions/cm2, and however, at the fluences of $1\times 10^{{12}}$ and $2\times 10^{{12}}$ ions/cm2, the SBH increased to 1.93 and 2.03 eV, respectively. Also, the ideality factor (IF) increased from 1.07 to 1.38. The in situ ${C}$ – ${V}$ measurements showed a similar trend, as the SBH decreased from 2.04 to ~1.88 eV until $5\times 10^{{11}}$ ions/cm2, but it increased to 2.14 and 2.56 eV at $1\times 10^{{12}}$ and $2\times 10^{{12}}$ ions/cm2, respectively. In addition, the doping concentration decreased from $1.01\times 10^{{16}}$ to $0.27\times 10^{{16}}$ cm $^{-{3}}$ as the defects increased significantly at the fluence of $2\times 10^{{12}}$ ions/cm2. The cathodoluminescence measurements revealed various Ga and O defects produced during SHI irradiation. Cross-sectional transmission electron microscopy measurements confirmed the formation of tracks within $\beta $ -Ga2O3 along the SHI path, and these results are explained with the inelastic thermal spike model.