Realization and optimization of enhanced and spectral selective photoluminescence in size and phase controlled nanocrystalline Ga2O3 films made by pulsed laser deposition

Realization and optimization of the optical properties for tunable and/or enhanced emission characteristics is critical to further advance the field of optoelectronics, photonics, and electronics for extreme environment applications. While recent advancements made to realize high-quality single crystals of Ga2O3, an interesting material for electronics and optoelectronics, strategies to obtain enhanced functionality and desired optical properties in nanocrystalline Ga2O3 without needing to expensive epitaxial systems or quite cumbersome equipment or rare-earth dopants remains a challenging problem for further development. In this context we have demonstrated high yield spectral selective photoemission, from pulsed laser deposited (PLD) un-doped Ga2O3 thin films with extensive control over nanocrystalline growth. Structural, interfacial and morphological investigation reveals the formation of perfect nanocrystalline seed layer promoting further growth of compact nano-columns with nano-textured atop. Optical spectroscopy demonstrates the desired control over band-edge absorption and realization of ideal photo-transition in perfectly oriented nano-columnar PLD β-Ga2O3 films. Ellipsometry shows the growth parameters dependent evolution of refractive index over broad spectral range. The findings as presented and described here provide evidence for controlled growth and realization of nanocrystalline β-Ga2O3 for functional device applications in optoelectronics in addition to provide a platform to further explore their futuristic technological applications.