Speaker
Description
The spinel-structured zinc gallate (ZnGa2O4) has received a lot of interest lately due to its broad bandgap, strong ultraviolet (UV) transmittance, and stability in vacuum. As a member of the transparent metal oxide semiconductor family, ZnGa2O4 is a potential phosphor due to its thermal and chemical stability as well as its blue emission when exposed to electrons with low voltage or UV radiation. The development of high-performance optoelectronic devices, particularly solar-blind photodetectors, requires materials with high thermal stability and wide bandgaps. In this work, ZnGa2O4 microrods were synthesized via a traditional solid-state reaction to investigate the correlation between their structural evolution and optical performance. The X-ray diffraction (XRD) analysis showed the successful formation of the ZnGa2O4 single phase, with the sharp and intense peaks confirming the high purity and crystallinity, with a crystal size of 61.16 nm and lattice constant of 8.326 Å. Nottably, no impurity peaks were detected, which indicates the superiority of this synthesis method in comparison with synthesis methods involving solutions. On the other hand, scanning electron microscope (SEM) revealed irregular rod-like shapes with various sizes from 2 to 10 µm as a result of the reaction time and annealing temperature. This could be as a result of anisotropic grain growth in the process of the reaction. Optical characterization using diffuse reflectance spectroscopy (DRS) followed by Tauc plot analysis determined a direct optical bandgap of 4.6 eV. The broad bandgap also makes sure that the material is not affected by the visible region of the solar spectrum, i.e., the material is intrinsically solar blind, thus enabling detection of the deep UV spectrum without interference from the visible solar spectrum. A second absorption peak found between 300 and 380 nm can be attributed to oxygen vacancies in the lattice, possibly contributing to persistent photoconductivity or increased sensitivity. The findings suggest that the high aspect ratio structure and the broad bandgap of the ZnGa2O4 microrods make them excellent candidates for photodetectors, offering efficient carrier transport and minimal dark current effects.
| Apply for student award at which level: | PhD |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |