Enhanced field emission properties of rGO wrapped Ga₂O₃ micro/nanobricks: Experimental investigation with theoretical validation

Aiming for efficient cold cathode applications in low dimension, pure and rGO wrapped gallium oxide micro/nanobricks were synthesized via cost-effective solid-state and hydrothermal routes. The synthesized samples were characterized using X-ray diffractometry, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and Raman spectroscopy for phase, morphology, composition, and structure-related investigations. In addition, all samples were thoroughly investigated, and as a result, experimental modifications were adapted accordingly for improving the field emission properties. Remarkable enhancement of field-emission performances with a high emission current-density of 1.08 mA/cm(2) and enhancement factor of 7400 has been observed as an effect of rGO wrapping. The results have been correlated with the increase in the availability of emission sites and proper charge carrier transport between the components in the hybrid structure. Furthermore, the probability of charge carrier transport across Ga2O3 irGO junction was validated using theoretical analysis via DFT calculations. Moreover, the improvement of field emission properties due to rGO wrapping was also predicted from ANSYS simulations. Hence, 3.5 times increment of current density and 2.5 times lowering of turn-on field, the Ga2O3/rGO hybrid system emerged as one of the most functional future cold cathodes. This work opens up new applications for Ga2O3-based composites beyond the sensing and catalysis sectors. (C) 2022 Published by Elsevier B.V.