Morphological Nucleation, Growth, and Self‐Assembly Evolutions of Nanosheets from GaO(OH) to Ellipsoid‐Like Hierarchical α‐Ga ₂ O ₃ and β‐Ga ₂ O ₃ for Photodetector Applications

Abstract As efficient and fast‐growing method with lower cost, reflux condensation is used to produce Ga 2 O 3 without the need for doping. Moreover, there are fewer readily available studies on the band gaps of α‐Ga 2 O 3 and GaO(OH), which are emerging as promising materials for photodetectors. This study demonstrated the conversion of GaO(OH) into the thermodynamically stable phases of α‐Ga 2 O 3 and β‐Ga 2 O 3 . Smaller Ga 3+ concentrations led to the rapid deposition of smaller particles onto larger ones, resulting in a decrease in the diameters. The faster spreading along the principal axial direction orientated the growth of particles, shaping the geometric anisotropy. The particles were confirmed by XRD, Raman, and FTIR analyses. Size distributions were presented in DLS graphs. Nucleation, Ostwald ripening, self‐assembly of nanosheets, and smaller aspect ratios were observed in FEG‐SEM. Intermediate products were identified at lower aging temperatures. EDS provided a qualitative chemical analysis. Optical transmittance spectra demonstrated high transparency and crystallinity. Band gaps were estimated from reflectance diffusive spectra. The donor–acceptor pair or electron‐hole recombination generated UV‐blue emissions. An improvement of PL emission band intensity value was observed with lower Ga 3+ concentration, as well as the compounds obtained at high‐temperature calcination. These findings support the potential of Ga 2 O 3 as photodetectors.