Investigating the structural, morphological, electrical, and optical characteristics of β-Ga₂O₃ synthesized by solid-state combustion

This study investigates the structural, morphological, electrical, and optical characteristics of β-Ga₂O₃ nano powder synthesized via the solid-state combustion method, emphasizing its potential applications in optoelectronics. A comprehensive suite of characterization techniques including XRD, FTIR, SEM, EDX, UV–Vis DRS, Raman, and PL spectroscopy was employed to analyse the β-Ga₂O₃ nanostructure. XRD confirmed the complete phase transformation of the γ-Ga₂O₃ precursor into the thermodynamically stable β-Ga₂O₃ after annealing at 900 °C for 3 h. Further analysis revealed minimal micro strain within the β-Ga₂O₃ lattice. Field emission scanning electron microscopy (FESEM) showed nearly spherical, polydisperse nanograins with an average size of 48.14 ± 1.30 nm. Energy-dispersive X-ray spectroscopy (EDX) verified the presence of gallium and oxygen as the primary elements, with an average stoichiometry of 2:3. FTIR identified characteristic vibrational absorption peaks at 436 and 668 cm⁻¹. Raman spectroscopy detected three active frequency modes, consistent with existing literature. Optical properties, assessed via UV–Vis DRS, indicated an absorption edge for β-Ga₂O₃ at 236 nm. Photoluminescence spectroscopy revealed a broad emission band spanning 400–600 nm, with six distinct Gaussian peaks centered at 426 nm (violet), 441 nm (blue), 465 nm (blue), 488 nm (cyan), 538 nm (green), and 571 nm (yellow). To evaluate DC conductivity, a thin pellet of β-Ga₂O₃ was prepared, and electrical measurements exhibited ohmic behaviour within the 0–30 V range.