Optical Characteristics of GaN Thin Film Deposited by Pulsed Laser Ablation 

Abstract

We present optical data on GaN thin film samples grown by pulsed laser ablation, two different pulsed laser ablation powers. The bandgap of specimens with recognizable crystallinity has been deduced from the optical spectrum data. Longtails were observed below the gap band. In specimens are entirely dependent on the powers of the laser ablation process. The specimens with the highest laser power, 2000 mJ, show that a smaller near band edge emission peaked at 3.32 eV is observed up to room temperature. The maximum energy bandgap 3.62 is possibly observed at 1500 mJ laser energy.