Rectifying Effect of the Sr₃Al₂O₆/Ga₂O₃ Heterojunction

Abstract

Oxide semiconductors, including binary and ternary oxides, are promising to be utilized as active layers in electronics. The heterojunctions based on oxides exhibit many attractive physical and structural properties and are preferably used to fabricate devices. Herein, Sr 3 Al 2 O 6 /Ga 2 O 3 heterojunction is fabricated using radiofrequency magnetron sputtering on silicon substrate, which shows an enhanced current-voltage characteristic under the 254 nm ultraviolet light illumination due to the photogenerated carriers in Ga 2 O 3 . In addition, the heterojunction provides evident rectified properties in the dark, and the improved rectified properties can be obtained under the 254 nm UV light illumination due to the electron-hole pairs separation in the depletion region due to the built-in electric field, while the rectified ratio decrease from %700 at AE0.5 to %20 V at AE5 V, which is due to the electron tunneling caused by shrinking depletion layer. Moreover, the band offsets of the heterojunction is determined by the X-ray photoelectron spectroscopy, which suggests a type I alignment with conduction band offset of 0.94 AE 0.02 eV and valence band offset of 0.53 AE 0.02 eV. The interfacial energy band offsets verify the potential implication for their rectifying property.

Fabrication of ϵ-Ga2O3 solar-blind photodetector with symmetric interdigital Schottky contacts responding to low intensity light signal

“…The effective confinement of electrons contributes to a consistent evolutive manner with the results in figure 3(b). While at 5 V, the I photo almost near-linearly go up with the increasing light intensity from 5 to 40 µW cm −2 as shown in figure 4(d), suggesting an approximate linear increasing photogenerated carriers proportional to the UV light generated rate and a reliable, stable operation under illuminations [22,43]. As indicated in figure 4(d), the photocurrents increase with the light intensity since more photons are absorbed in the ε-Ga 2 O 3 and more carriers are photogenerated in the ε-Ga 2 O 3 channel under the illumination of a higher light intensity.…”

Current advances in solar-blind photodetection technology: using Ga2O3 and AlGaN

“…To date, Ga 2 O 3 heterostructures based on graphene, 141 polyaniline (PANI), 29 Sr 3 AlO 6 , 142 MoS 2 , 143 GaN, 144 Nb:SrTiO 3 (NSTO), 145 PEDOT:PSS/Ga 2 O, 146 Au, 147 etc. have been reported for the fabrication of SB PDs with excellent performances and strong reproducibility.…”

Comparison of optoelectrical characteristics between Schottky and Ohmic contacts to β-Ga2O3 thin film

“…The performances of photodetectors, to a large degree, depend on the nature and modified properties of the selected materials [4]. Specifically, as one of the typical wide bandgap semiconductors, β-Ga 2 O 3 not only has a ultra-wide bandgap of 4.5-4.9 eV (responding in the UV solid-blind regime), but also a high thermal and chemical stability, high critical breakdown field of 6-8 MV/cm (allowing high voltage and strong radiation operations) [5,6], therefore allowing them to be extensively employed to fabricate UV solar-blind photodetectors [7] in the form of thin films [8][9][10][11][12], bulk single crystals [13][14][15][16], nanostructures [17][18][19][20] and heterogeneous structures [20][21][22][23][24][25][26].…”