Recent progress on the effects of impurities and defects on the properties of Ga₂O₃

Abstract

Ga2O3 is widely applied in power devices and solar-blind ultraviolet photodetectors due to its ultra-wide bandgap, large breakdown field, and favorable stability. However, it is difficult to prepare the ideal...

Directional Carrier Transport in Micrometer-Thick Gallium Oxide Films for High-Performance Deep-Ultraviolet Photodetection

“…The distinct defect distribution between the interface region and the top film provides valuable insights into understanding the dramatic enhancement of responsivity with faster response time occurring at a thickness far larger than d p . It is well established that material defects, in the form of lattice disorders and surface defects, widely exist for films grown on heterogeneous substrates. , This is particularly true for the film growth with large lattice mismatch, such as the case of ε-Ga 2 O 3 on sapphire in this study. The STEM image in Figure a identifies a disordered interface region with a high density of misfit dislocations and domain boundaries, in particular for the initial 100–150 nm region, which is consistent with the XPS observation.…”

Effect of lanthanum doping on structural, optical, and photocatalytic properties of YVO4

“…Accordingly, the effect of La 3+ dopant ion has emerged based on the luminescence properties of the undoped material since they have same host crystal. In previous studies with similar results demonstrates doping of impurities with different oxidation state can create or increase defect levels[27, 28]. The impurity ions could give raise to either radiative or non-radiative recombination.…”

Stress Relaxation Due to Dislocation Formation in Orthorhombic Ga2O3 Films Grown on Al2O3 Substrates

“…Gallium oxide (Ga2O3), one of the ultra-wide bandgap semiconductors, has attracted much attention in recent years due to great prospects in power electronic devices including those for space and nuclear industries, photoelectric converters for the ultraviolet region, high-power radio frequency devices, gas sensors, etc. [1][2][3]. An important feature of Ga2O3 is the possibility of its existence in various polymorphic forms: stable monoclinic β-phase, and metastable α-, γ-, κ-, ε-and δ-phases with their specific characteristics and benefits [4][5][6][7][8].…”

“…However, until now, some works indicate the possibility of the existence of pure ε-phase [12]. Despite the ongoing debate about the real structure of the considered phase, most scientific groups tend to consider the phase as composed of 3-fold rotational orthorhombic domains with disordered domain boundaries [10,11,13,14]; the single-domain orthorhombic structure of this phase has been recently demonstrated [3,15]. Therefore, in this work, we will consider this phase as κ-Ga2O3 with the orthorhombic crystal structure Pna21.…”

“…The heterostructures based on κ-Ga2O3 are successfully used in solar blind photodetectors [16], powerful Schottky diodes [17], and in high-frequency applications [18]. Unfortunately, the characteristics of these devices are limited by the crystal quality of the κ-Ga2O3 film/layer/heterostructures, which are characterized by a high dislocation density that ranges from 5.2×10 7 to 1.4×10 13 cm -2 [3,19]. Such a wide scatter in the value of the dislocation density can be due to the insufficient knowledge on the optimal parameters of the heterostructure, including substrate material, crystallographic orientation of the substrate, film thickness, etc.…”