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Geometric and Thermal Control of κ- to β-Ga2O3 Phase Engineering for High-Performance Solar-Blind Photodetector
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DOI:10.1016/j.mtphys.2026.102105.png)
Abstract
En 中文
By varying the growth temperature in metalorganic chemical vapor deposition (MOCVD), we achieved controlled growth of (002)-oriented κ-Ga2O3, a κ-β mixed phase, and (-201)-oriented β-Ga2O3 on c-plane sapphire. The highly aligned orientation of κ-Ga2O3 grains is attributed to a superior lattice symmetry match with the c-plane sapphire substrate, as evidenced by a narrow ω-scan rocking curve ( FWHM<0.6°). To achieve β-Ga2O3 films with superior crystallinity, a post-growth annealing strategy was employed to transform the metastable κ-phase into the thermodynamically stable β-phase. At an optimized annealing temperature of 1000 °C, the resulting β-Ga2O3 film exhibits significant improvements in both crystal quality and surface morphology. The FWHM of the (-201) rocking curve was drastically reduced from the as grown 2.25° to 0.77°, and the surface roughness is reduced from 11.3 nm to 4.17 nm. At 10 V bias, the β-Ga2O3 based solar-blind ultraviolet (UV) photodetector achieves a responsivity of 98 A/W, a detectivity of 1.3 × 1017 Jones and a high UV/visible rejection ratio (Rmax/R400) exceeding 106. This work establishes a reliable approach for controllable preparation of Ga2O3 films with different phases and for the fabrication of high-quality β-Ga2O3 films suitable for optoelectronic device applications.
Keywords:
κ-Ga2O3
β-Ga2O3
phase engineering
MOCVD
photodetector
Journal
IF:
9.7
Papers:
2.0K
Citations:
1.2W
