Photoluminescence and Raman Scattering Characterization of GaN, InGaN and AlGaN Films Using a UV Excitation Raman-Photoluminescence Microscope

摘要

A combined room temperature photoluminescence (PL) and Raman scattering study was performed on a series of GaN, InGaN and AlGaN epitaxial films grown on sapphire by low pressure metalorganic chemical vapor deposition, using a UV Raman-PL microscope. Each PL or Raman spectrum was taken within a few seconds or minutes, with fine and weak features obtained superior than using other spectrometers. Accurate information about the band gap energy, alloy composition, material properties and structures, in particulr for low composition ternaries, was obtained. The rapid feedback of the material properties with the growth process was realized. The combined PL and Raman features, their variations with excitation power, energy, and resonance are studied with respect to the material characteristics, structures and parameters.