The variety of semiconductor materials has been extended in various directions, for example, to very wide bandgap materials such as oxide semiconductors as well as to amorphous semiconductors. Crystalline β-Ga₂O₃ is known as a transparent conducting oxide with an ultra-wide bandgap of ~4.9 eV, but amorphous (a-) Ga₂O_x is just an electrical insulator because the combination of an ultra-wide bandgap and an amorphous structure has serious difficulties in attaining electronic conduction. This paper reports semiconducting a-Ga₂O_x thin films deposited on glass at room temperature and their applications to thin-film transistors and Schottky diodes, accomplished by suppressing the formation of charge compensation defects. The film density is the most important parameter, and the film density is increased by enhancing the film growth rate by an order of magnitude. Additionally, as opposed to the cases of conventional oxide semiconductors, an appropriately high oxygen partial pressure must be chosen for a-Ga₂O_x to reduce electron traps. These considerations produce semiconducting a-Ga₂O_x thin films with an electron Hall mobility of ~8 cm²V⁻¹ s⁻¹, a carrier density N_e of ~2 × 10¹⁴ cm⁻³ and an ultra-wide bandgap of ~4.12 eV. An a-Ga₂O_x thin-film transistor exhibited reasonable performance such as a saturation mobility of ~1.5 cm² V⁻¹ s⁻¹ and an on/off ratio >10⁷.

半导体材料的种类已在各个方向上扩展，例如，扩展到带隙很宽的材料，例如氧化物半导体以及非晶半导体。结晶的β-Ga ₂ ö ₃被称为与超宽带隙〜4.9电子伏特的透明导电氧化物，但无定形的（A-）镓₂ ö _X仅仅是一个电绝缘体，因为超宽带隙的组合和无定形结构在获得电子传导方面有严重的困难。本文报道了半导体a-Ga ₂ O _x通过抑制电荷补偿缺陷的形成，可以在室温下沉积在玻璃上的薄膜及其在薄膜晶体管和肖特基二极管上的应用。膜密度是最重要的参数，并且通过将膜生长速率提高一个数量级来增加膜密度。另外，与常规氧化物半导体的情况相反，必须为a-Ga ₂ O _x选择适当高的氧分压以减少电子陷阱。这些考虑产生了电子霍尔迁移率为〜8 cm ² V ^-1  s ^-1，载流子密度为N的半导体a-Ga ₂ O _x薄膜。_e为〜2×10 ¹⁴  cm ^-3，超宽带隙为〜4.12 eV。a-Ga ₂ O _x薄膜晶体管表现出合理的性能，例如〜1.5 cm ²  V ^-1  s ^-1的饱和迁移率和> 10 ⁷的开/关比。