Study of the linear electro-optic effect in α-GaN by electroreflectance

The linear electro-optic (Pockels) effect for hexagonal GaN was studied by electrolytic electroreflectance spectroscopy. The electric field strength and space charge region parameters were extracted from Franz–Keldysh oscillations and photocurrent spectra. Data analysis yielded for the linear electro-optic coefficient r13 a value of (1.55±0.08) pm V−1 indicating an appreciable ionic contribution which can be related to the converse piezoelectric effect.