Pulsed laser deposition is employed to fabricate as-grown amorphous and post-growth annealed crystalline β-Ga2O3 films. The films annealed at temperatures above 600 °C are found to exhibit a pure monolithic phase with a bandgap of 4.7 eV. The thermally activated donor ionization and dielectric relaxation of these films are systematically investigated by temperature-dependent DC and AC conductivity measurements, and complex electric modulus analysis. A donor level at ∼180 meV below the conduction band edge and a small polaron tunneling (SPT) relaxation with an activation energy of ∼180 meV are observed in the as-grown amorphous Ga2O3 film but not in the monolithic β-Ga2O3 film. The SPT occurs between donor sites with its thermal relaxation of polarization being associated with the thermal ionization of the donor state. Thermal annealing of the amorphous films removes the 180 meV donors as well the corresponding SPT relaxation.

中文翻译：

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Ga2O3 中小极化子隧穿弛豫与施主电离的相关性

脉冲激光沉积用于制造生长非晶和生长后退火的晶体 β-Ga2个欧3个电影。发现在高于 600 °C 的温度下退火的薄膜显示出带隙为 4.7 eV 的纯单片相。通过温度相关的直流和交流电导率测量以及复电模量分析，系统地研究了这些薄膜的热激活供体电离和介电弛豫。在生长的非晶 Ga 中观察到导带边缘以下约 180 meV 的施主能级和活化能约 180 meV 的小极化子隧穿 (SPT) 弛豫2个欧3个薄膜，但不在单片 β-Ga 中2个欧3个电影。SPT 发生在施主位点之间，其极化热弛豫与施主态的热电离有关。非晶薄膜的热退火去除了 180 meV 供体以及相应的 SPT 弛豫。