其他名称：
25-29-00627
项目负责人：
Shapenkov Sevastian
发表日期：
2025
主持机构：
Ioffe Institute,
国家：
俄罗斯
开始日期：
2025
结束日期：
2026
简介：
Synthesis of wide-gap p-type semiconductors and formation of heterostructures using them has been an important scientific and technical problem for many years. Successful work in this area for gallium nitride was awarded with the Nobel Prize in 2014. The discovery of the p-type in GaN formed the basis for the development and production of LED lamps. [1]
Advances over the past two decades in the growth technologies of the ultra-wide-bandgap (4.6-5.3 eV) gallium oxide semiconductor, Ga2O3, have shown prospects for its use in next-generation electronic devices, including X-ray and solar-blind ultraviolet photodetectors, high-power power transistors, and low-temperature gas sensors. However, the problem of obtaining effective p-type conductivity with noticeable hole mobility for Ga2O3 remains open [2]. Its solution rests on the electronic activity of gallium oxide’s own point defects, which act as electrons donors . Despite the active research in this direction and multiple attempts to use various elements for doping (N, Zn, Mg, etc.), there are no noticeable achievements, which hinders the practical implementation of gallium oxide.
The term “gallium (III) oxide” refers to a group of its five polymorphs with different crystal structures. Among them, the main ones can be distinguished: the thermostable monoclinic β-phase and the metastable trigonal α-Ga2O3 with a corundum structure and the pseudohexagonal (orthorhombic) ε(κ)-Ga2O3. Due to crystallographic compatibility with sapphire, silicon carbide, gallium nitride, etc., in the case of heteroepitaxy, it is possible to create gallium oxide heterostructures with other semiconductors having natural p-type conductivity.
The most common approach for obtaining a pn-heterojunction in prototype Ga2O3-based semiconductor devices is to deposit a layer of nickel oxide, NiOx, on its surface. It has fairly good adhesion to gallium oxide, regardless of the type of its polymorph, and the resulting pn-junction is characterized by satisfactory electrical properties. However, NiOx, on the one hand, has a band gap noticeably smaller than gallium oxide (3.6 - 4 eV), and on the other hand, this oxide is less thermally stable than Ga2O3. Therefore, the theoretically possible electrical breakdown field of 8 MV/cm for gallium oxide is not achieved, which initially attracted attention to it, since it is approximately 2.5 times higher than that of GaN-based power transistors. [2,3].
This grant application proposes to produce pn-heterojunctions with gallium oxide using epitaxy of layers of ultra-wide-bandgap p-type transparent conductive oxides (TCO). Ultra-wide-gap TCOs include simple and complex oxides of Ga, Cr, V, Zn, In, etc., as well as their solid solutions with each other and with Al. The similarity of their crystal structure and the chemistry of epitaxy processes makes it possible to create double and more complex heterostructures. Previously, only isolated experiments were made [4], and most of the available scientific works contain only information about the deposition of nano-sized layers of ultra-wide-bandgap TCO on some commercial substrate. We propose to grow micron scale epitaxial crystalline films of p-type TCO (ZnGa2O4, CuGaO2, GaCrO3 etc.) by ultrasonic vapor chemical epitaxy (mist-CVD) in heterostructures with gallium oxide and study their crystallographic and electrical properties.
The success of this research in the future can give a significant impetus to the development of device technology based on gallium oxide and form the basis for the transition to its industrial application, which meets modern needs of science and technology.
专业领域：
材料科学
语种：
英语
