Gallium Nitride Raman Spectrum

GaN is an attractive material from the point of view of its existing and prospective applications in blue/UV light emitters/lasers as well as high-power electronics. Thus, for example, GaN-based blue laser diodes (LDs) and green and blue light-emitting diodes (LEDs) have already been commercialized as a result. All LDs, LEDs, and other such devices have a multilayer structure grown on an epitaxial GaN thin layer, few microns thick, on a sapphire substrate. For this reason, the characterization of the epitaxial GaN on sapphire is of critical importance.

Raman spectroscopy of GaN

GaN Raman spectra allow us to determine nondestructively the electrical properties of the material using optical techniques. The spectral difference between the GaN/sapphire interface and the GaN layer indicates the spatial variation in the strains in the direction of the film growth, within a thickness of few microns. Therefore, GaN Raman spectroscopy enables easy and quick nondestructive material characterization, ensuring prompt feedback of the data on the grown material.