Quantum-confined Stark shift in electroreflectance of a cylindrical GaN quantum dot

The electroreflectance (ER) spectra in the presence of the modulated electric field have been employed to study the fine structure of a cylindrical GaN quantum dot (QD), including the light hole and heavy hole interband transitions, and the ER spectra exhibit Franz–Keldysh oscillation characteristics with abscissa of energy (E−Eg). The quantum-confined Stark shift (QCSS) happened when the electric field intensity increased and the light and heavy holes dependent characteristics have been shown. The three-dimensional Schrödinger equation of QD has been calculated within the framework of effective-mass approximation, and the ER indices have been obtained from modulation absorption coefficients using the Seraphin coefficients and the Kramer–Kroning relation.