The electrical characteristics and microstructures ofβ-Ga_(2)O_(3) Schottky barrier diode(SBD)devices irradiated with swift heavy ions(2096 MeV Ta ions)have been studied.It was found thatβ-Ga_(2)O_(3) SBD devices sh...The electrical characteristics and microstructures ofβ-Ga_(2)O_(3) Schottky barrier diode(SBD)devices irradiated with swift heavy ions(2096 MeV Ta ions)have been studied.It was found thatβ-Ga_(2)O_(3) SBD devices showed the reliability degradation after irradiation,including turn-on voltage Von,on-resistance Ron,ideality factor n,and the reverse leakage current density Jr.In addition,the carrier concentration of the drift layer was decreased significantly and the calculated carrier removal rates were 5×10^(6)-1.3×10^(7)cm^(-1).Latent tracks induced by swift heavy ions were observed visually in the wholeβ-Ga2O3 matrix.Furthermore,crystal structure of tracks was amorphized completely.The latent tracks induced by Ta ions bombardments were found to be the reason for the decrease in carrier mobility and carrier concentration.Eventually,these defects caused the degradation of electrical characteristics of the devices.In terms of the carrier removal rates,theβ-Ga_(2)O_(3) SBD devices were more sensitive to swift heavy ions irradiation than SiC and GaN devices.展开更多
Polycrystalline samples of La2Zr2O7 pyrochlore are irradiated by different energetic heavy ions to investigate the dependence of the vibrational mode variations on the irradiation parameters. The applied electronic en...Polycrystalline samples of La2Zr2O7 pyrochlore are irradiated by different energetic heavy ions to investigate the dependence of the vibrational mode variations on the irradiation parameters. The applied electronic energy loss(d E/dx)e increases from about 5.2 keV/nm to 39.6 keV/nm. The ion fluence ranges from 1× 10^11 ions/cm^2 to 6× 10^15 ions/cm^2.Vibrational modes of irradiated pyrochlore are analyzed by using Raman spectrum. Infrared active modes F1 uat 192, 308,and 651 cm^-1 appear in Raman spectra, and the F2 gband at 265 cm-1 rises up due to the irradiation by 200-MeV Kr ions with(d E/dx)e of 16.0 keV/nm. Differently, for the pyrochlore irradiated by 1750-MeV Bi ions with(d E/dx)e of 39.6 keV/nm, in spite of the appearance of infrared active mode F1 u651 cm^-1, the amorphous structure occurs according to the vibrational mode variations of pyrochlore irradiated at higher ion fluences. Amorphous tracks are observed in the samples, which confirm the occurrence of pyrochlore–amorphous transition in pyrochlore irradiated with(d E/dx)e of 39.6 keV/nm.展开更多
基金the National Natural Science Foundation of China(Grant Nos.12035019,11690041,and 12075290)China National Postdoctoral Program for Innovative Talents(Grant No.BX20200340)+1 种基金China Postdoctoral Science Foundation(Grant No.2020M673539)CAS"Light of West China"Program,and the Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS)(Grant No.2020412).
文摘The electrical characteristics and microstructures ofβ-Ga_(2)O_(3) Schottky barrier diode(SBD)devices irradiated with swift heavy ions(2096 MeV Ta ions)have been studied.It was found thatβ-Ga_(2)O_(3) SBD devices showed the reliability degradation after irradiation,including turn-on voltage Von,on-resistance Ron,ideality factor n,and the reverse leakage current density Jr.In addition,the carrier concentration of the drift layer was decreased significantly and the calculated carrier removal rates were 5×10^(6)-1.3×10^(7)cm^(-1).Latent tracks induced by swift heavy ions were observed visually in the wholeβ-Ga2O3 matrix.Furthermore,crystal structure of tracks was amorphized completely.The latent tracks induced by Ta ions bombardments were found to be the reason for the decrease in carrier mobility and carrier concentration.Eventually,these defects caused the degradation of electrical characteristics of the devices.In terms of the carrier removal rates,theβ-Ga_(2)O_(3) SBD devices were more sensitive to swift heavy ions irradiation than SiC and GaN devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11705246,11675233,and 11690041)the Natural Science Foundation of Gansu Province,China(Grant No.17JR5RA316)
文摘Polycrystalline samples of La2Zr2O7 pyrochlore are irradiated by different energetic heavy ions to investigate the dependence of the vibrational mode variations on the irradiation parameters. The applied electronic energy loss(d E/dx)e increases from about 5.2 keV/nm to 39.6 keV/nm. The ion fluence ranges from 1× 10^11 ions/cm^2 to 6× 10^15 ions/cm^2.Vibrational modes of irradiated pyrochlore are analyzed by using Raman spectrum. Infrared active modes F1 uat 192, 308,and 651 cm^-1 appear in Raman spectra, and the F2 gband at 265 cm-1 rises up due to the irradiation by 200-MeV Kr ions with(d E/dx)e of 16.0 keV/nm. Differently, for the pyrochlore irradiated by 1750-MeV Bi ions with(d E/dx)e of 39.6 keV/nm, in spite of the appearance of infrared active mode F1 u651 cm^-1, the amorphous structure occurs according to the vibrational mode variations of pyrochlore irradiated at higher ion fluences. Amorphous tracks are observed in the samples, which confirm the occurrence of pyrochlore–amorphous transition in pyrochlore irradiated with(d E/dx)e of 39.6 keV/nm.
