Band Offset Measurements of ε-(InxGa1-x)2O3/AlN using X-ray Photoelectron Spectroscopy
In the pursuit of advanced electronic applications, such as deep ultraviolet photodetectors, high-electron-mobility transistors, and high-power electronic devices, InGaO/AlN heterojunctions hold significant promise due to their ultra-wide band gap, tunable polarization properties, and optimized spectral response. In this regard, the ε-(In0.15Ga0.85)2O3 /AlN heterojunction has significant potential for high-performance optoelectronic devices, particularly in extreme environments, due to its tunable bandgap, tunable band alignment, and enhanced thermal management with AlN's high thermal conductivity (~321 W/m·K). This study focuses on the growth of ε-(In0.15Ga0.85)2O3 on AlN substrates via pulsed laser deposition (PLD), along with an investigation of the resulting valence and conduction band offsets at the heterointerface. Through PLD growth optimization experiments, it was observed that moderate temperature (550 ℃), high oxygen pressure (1.25×10⁻² Torr), and high laser energy density (1.38 J cm-2) are essential for the deposition of the metastable ε-(In0.15Ga0.85)2O3 phase. The heterojunction exhibited a conduction band offset exceeding 1 eV, while the valence band offset was found to be below 0.1 eV. These band offsets suggest that while the heterojunction effectively restricts electron leakage from the naturally n-type ε(In0.15Ga0.85)2O3 to AlN, it may not be as efficient in limiting the hole leakage. These findings have significant implications for the development of next-generation electronic devices based on InGaO/AlN heterostructures.
band alignment, ultra wide bandgap heterojunction
Sultana, M. (2024). Band offset measurements of ε-(InxGa1-x)2O3/AlN using x-ray photoelectron spectroscopy. [Master's thesis, Texas State University].
Networked Digital Library of Theses and Dissertations