Cathodoluminescence and Field-Emission Properties of β-Ga_2O_3 Nanobelts

摘要

β-Ga_2O_3 nanobelts were synthesized using a vapor transport process in a controlled ambient. Structural characterization revealed that the as-synthesized samples consisted of monoclinic β-Ga_2O_3 nanobelts, and the presence of gallium-associated defects was verified using cathodoluminescence (CL). The formation of gallium-associated defects was explained by the insufficiency of the supply of cations, generating gallium vacancies on the (010) facet during growth. Furthermore, field-emission measurements indicated that β-Ga_2O_3 nanobelts exhibited defect-related electron emission. The turn-on fields of β-Ga_2O_3 nanobelts increased significantly with the degree of structural defects. For a sample prepared under 15% ambient oxygen, Fowler-Nordheim (F-N) analysis revealed two distinct field-enhancement factors of 1194 and 276, respectively. A correlation between field emission and structural defects was proposed. The experimental results demonstrate the presence of gallium-associated defects, which behave as electron traps, degrading the electron field-emission properties of β-Ga_2O_3 nanobelts.