Laser damage mechanism and in situ observation of stacking fault relaxation in a β-Ga2O3 single crystal by the EFG method

We designed an original and effective method to study the laser damage mechanism of a beta-Ga2O3 single crystal grown by the edge-defined film-fed growth (EFG) method. Structure destruction under irradiation with a high light field intensity of 1064 nm using an Nd:YAG laser was systematically studied in the beta-Ga2O3 crystal. Four typical crystal defects, namely, voids, amorphous and nanocrystalline layers and high density stacking faults, were found using a focused ion beam-dual beam scanning electron microscope (FIB-SEM) and a transmission electron microscope (TEM). For the first time, a laser damage mechanism in the beta-Ga2O3 subsurface layer was built up and illuminated by microstructure analysis. The stacking fault relaxation of the beta-Ga2O3 single crystal was observed in situ for the first time under electron beam irradiation. The cathodoluminescence (CL) spectrum further revealed the luminescence properties of the stacking faults.