Linear Electro-Optic Effect in Electroreflectance Spectra of AlGaN/InGaN/GaN Light Emitting Diodes Structures

Abstract

The linear electro-optic effect in InGaN/AlGaN/GaN pn-heterostructures for light emitting diodes, grown by metal–organic chemical vapor deposition on sapphire substrates and flip-chip mounted, was studied by electroreflectance spectroscopy. Interference fringes, whose parameters depend on the DC voltage applied on the pn-junction, were observed in electroreflectance spectra. Data analysis, based on a calculation of the built-in electric field in the depletion layer and linear electro-optic effect, yielded the linear electro-optic coefficient r 13 of 22±6 pm/V for hexagonal In0.12Ga0.88N.