Low-temperature growth of high-quality a-plane GaN epitaxial films on lattice-matched LaAlO3 substrates

Nonpolar GaN demonstrates a significant potential for application in the field of light-emitting diodes, polarization sensitive detectors, etc. However, the achievement of the high-quality nonpolar GaN epitaxial films still faces significant challenges. In this study, the high-quality nonpolar a-plane GaN epitaxial films have been obtained on the lattice-matched LaAlO3(100) substrates through the low-temperature pulsed laser deposition. The similar to 500 nm-thick nonpolar a-plane epitaxial films grown at 450 degrees C exhibit small full-width at half-maximum (FWHM) of 0.15 degrees and 0.20 degrees for GaN(11-20) and GaN(10-11) for the X-ray rocking curves, respectively, and very smooth surface with a root-mean-square roughness of 1.2 nm. In addition, sharp and abrupt GaN/LaAlO3 hetem-interfaces are observed. The developed GaN epitaxial films present strong potential of application in the field of UV detection and curing in the near future.