Band offsets in ITO/Ga2O3 heterostructures

Abstract

The valence band offsets in rf-sputtered Indium Tin Oxide (ITO)/single crystal β-Ga 2 O 3 (ITO/Ga 2 O 3) heterostructures were measured with X-Ray Photoelectron Spectroscopy using the Kraut method. The bandgaps of the component materials in the heterostructure were determined by Reflection Electron Energy Loss Spectroscopy as 4.6 eV for Ga 2 O 3 and 3.5 eV for ITO. The valence band offset was determined to be-0.78 ± 0.30 eV, while the conduction band offset was determined to be-0.32 ± 0.13 eV. The ITO/Ga 2 O 3 system has a nested gap (type I) alignment. The use of a thin layer of ITO between a metal and the Ga 2 O 3 is an attractive approach for reducing contact resistance on Ga 2 O 3-based power electronic devices and solar-blind photodetectors.

X‐ray photoelectron spectroscopy characterization of band offsets of MgO/Mg2Si and SiO2/Mg2Si heterojunctions

“…REELS were obtained using a 1-kV electron beam and the hemispherical electron analyzer that is part of the XPS system. REELS is a surface sensitive technique capable of analyzing electronic structures of ultrathin gate oxide materials because the low-energy-loss region reflects the valence and conduction band structures, 17,18 and the REELS technique is a good choice for to determining bandgap for higher band gap (>5 eV) materials where there is a distinct energy loss transition. 19 In order to obtain the core level spectra of all samples and the valence band spectra of the bulk samples, the XPS analysis was performed using the Al-Kα X-ray source (hν = 1,486.6 eV) from the F I G U R E 3 X-ray photoelectron spectroscopy (XPS) survey scans of thick MgO, 5-nm MgO on Mg 2 Si, and thick Mg 2 Si samples UTRA DLD instrument company in Shimazu, Japan.…”

“…many high k dielectric materials to choose, it seems that MgO (k = 9.8) 11 and SiO 2 (k = 3.9) 12,13 should be given priority because MgO and SiO 2 are natural oxidizing layers on the surface of Mg 2 Si, [14][15][16] and normally, a native oxide would be useful for manufacturability and reliability. 17 If the heterojunction formed by the natural oxide layer and Mg 2 Si meets the required band offset, the effort to find other suitable dielectric materials can be reduced. were used to obtain sample 1-3 thick film (bulk) samples.…”

Transport Mechanism of Enhanced Performance in an Amorphous/Monoclinic Mixed-Phase Ga2O3 Solar-Blind Deep Ultraviolet Photodetector

“…To unravel the transport mechanism of enhanced performance in an amorphous/monoclinic mixed-phase Ga 2 O 3 solar-blind photodetector, further research was conducted in combination with experimental and theoretical calculations. The interface between insulating oxide channels is considerably important, and the band offset at the edges of the conduction band and valence band largely determines the PD performance [51,52]. According to the method proposed by Kraut et al [53], by extracting scanning data from the X-ray photoelectron spectroscopy (XPS), the band alignment of amorphous/monoclinic mixed-phase Ga 2 O 3 can be obtained.…”

Valence and conduction band offsets for sputtered AZO and ITO on (010) (Al0.14Ga0.86)2O3

“…One potential method for reducing the contact resistance is to include a lower gap transparent conducting oxide as an interlayer between the metal and the wide bandgap semiconductor [22][23][24][25][26][27]. The most commonly used TCOs are indium tin oxide (ITO) and aluminum zinc oxide (AZO).…”