A magnetotransport study of AlGaN/GaN heterostructures on silicon

Abstract

Resistivity and Hall effect measurements as functions of temperature and magnetic field have been made on AlGaN/GaN heterostructures grown on silicon substrates. Electronic properties are comparable to those of similar structures grown on sapphire or silicon carbide. Persistent photocurrent (PPC) effects induced by illumination with blue and ultraviolet (UV) light-emitting diodes (LEDs) have been investigated. These effects persisted to room temperature. Shubnikov-de Haas (SdH) oscillations were observed in several samples but only after illumination in some samples. Analysis of the mobility dependence on the carrier density suggests small angle scattering is responsible for the suppression of the oscillations prior to illumination in those samples.