Investigation of the absorption coefficient, refractive index, energy band gap, and film thickness for Al0.11Ga0.89N, Al0.03Ga0.97N, and GaN by optical transmission method

The design of optoelectronic devices fabricated from III-Nitride materials is aided by knowledge of refractive index and absorption coefficient of these materials .The optical properties of Al0.11Ga0.89N, Al0.03Ga0.97N, and GaN grown by MOVPE on sapphire were investigated by means of transmittance measurements .The optical transmission method is successfully used to determine the refractive index (n), absorption coefficient (α), film thickness and energy gap of three samples of film over the spectral range of (1-5 eV)