Abstract
Laser-patterned (0001) sapphire has been evaluated as a substrate to perform GaN epitaxial lateral overgrowth (ELO) by metal-organic chemical vapor deposition (MOCVD). Several conditions of trench ablation were tested by varying scanning speed and laser fluence of a 266-nm picosecond laser. Growth of GaN epilayers was characterized by micro photoluminescence and cathodoluminescence (CL) spectroscopy. The spectra revealed a strain relaxation in the epitaxially overgrown GaN layer with improved quality expressed by enhanced intensity and redshift of the bandgap luminescence (from 3.44 to 3.40 eV). The bandgap against yellow luminescence (YL) intensity ratio also revealed that a defect-depleted area exists at the edge of the trench.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
