A Metal-Oxide Contact to ε-Ga₂O₃ Epitaxial Films and Relevant Conduction Mechanism

Abstract

In this work, the conduction mechanisms across novel contacts to epitaxial films of pure phase epsilon-Ga2O3 (ε-Ga2O3) were investigated. Different structures made by sputtered metal and oxide thin films were tested as electrical contacts. I-V characteristics show heterogeneous behaviors, revealing different conduction mechanisms according to the applied bias. The results are interesting as they offer a viable method to obtain ohmic contacts on ε-Ga2O3, which is less studied than other gallium oxide polymorphs but may find application in new electronic and optoelectronic devices. The newly developed ohmic contacts allow to fabricate simple test devices and assess the potential of this material.

Orthorhombic undoped κ-Ga2O3 epitaxial thin films for sensitive, fast, and stable direct X-ray detectors

“…, the dark current) at different applied bias voltages, as well as to investigate on the presence of possible non-linear charge transport mechanisms ( e.g. , space charge limited current, 37 or Frenkel–Poole emission 38 ), which are well-known to negatively affect the performance of detectors based on the direct conversion of X-rays into electric charge.…”

“…Before irradiation under X-rays, the photoconductive detector was characterized in dark conditions to quantify the background noise level (i.e., the dark current) at the different applied bias voltages, as well as to investigate on the presence of possible non-linear charge transport mechanisms (e.g., space charge limited current 37 , or Frenkel-Poole emission 38 ), which are well-known to negatively affect the performance of detectors based on the direct conversion of X-rays into electric charge. Moreover, as can be inferred from Fig.…”

Silane‐Mediated Expansion of Domains in Si‐Doped κ‐Ga2O3 Epitaxy and its Impact on the In‐Plane Electronic Conduction

“…For a selected number of samples, an additional investigation in the 10–300 K temperature range was performed. For this purpose Ti/Au [ 28 ] or SnO 2‐x /ITO/Au [ 64 ] Ohmic contacts were fabricated with a sputtering technique on the corners of squared shaped samples.…”

Enhancement of crystalline quality and solar-blind photodetection characteristics of ε-Ga2O3 films by introducing Zn impurity

“…[14][15][16][17] Among them, the most stable crystal structure is b-Ga 2 O 3 , 18,19 whereas e-Ga 2 O 3 is the metastable phase second only to b-Ga 2 O 3 . 20,21 Compared to b-Ga 2 O 3 , e-Ga 2 O 3 has a similar wide bandgap (B4.9 eV), higher lattice symmetry, lower anisotropic crystal structure, and lower growth temperature. [22][23][24][25] In recent years, research studies on solar-blind UV detectors based on e-Ga 2 O 3 thin films have begun to rise and are receiving increasing attention.…”