Improvement in a-plane GaN crystalline quality using wet etching method

摘要: Nonpolar (110) GaN films are grown on the etched a-plane substrates via metalorganic vapor phase epitaxy. High-resolution X-ray diffraction analysis shows great decreases in full width at half maximum of samples compared with those sample without etching, both on-axis and off-axis, indicating reduced dislocation densities improved crystalline quality these samples. The spatial mapping E2 (high) phonon mode demonstrates smaller line a black background wing region, which testifies enhanced epitaxial lateral overgrowth areas. Raman scattering spectra peaks exhibit in-plane compressive stress for all samples, shift toward lower frequency range, relaxations films. Furthermore, room temperature photoluminescence measurement significant decrease yellow-band emission intensity templates, also illustrates better optical properties