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

Abstract

• Nanocolumnar β-Ga 2 O 3 thin films were made by pulsed-laser deposition. • Performed detailed structural, interfacial and optical characterization of Ga 2 O 3 films. • Controlled processing conditions allow to tune the surface/interface microstructure. • Spectral selective photoluminescence demonstrated from nanotextured β-Ga 2 O 3 films. 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 Ga 2 O 3 , an interesting material for electronics and optoelectronics, strategies to obtain enhanced functionality and desired optical properties in nanocrystalline Ga 2 O 3 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 Ga 2 O 3 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-Ga 2 O 3 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-Ga 2 O 3 for functional device applications in optoelectronics in addition to provide a platform to further explore their futuristic technological applications.