Portal de Periódicos da CAPES

Surface photovoltage spectroscopy characterization of Al 1‐x In x N/AlN/GaN heterostructures

2011; Wiley; Volume: 9; Issue: 3-4 Linguagem: Inglês

10.1002/pssc.201100359

1862-6351

Saurabh Pandey, Daniela Cavalcoli, Beatrice Fraboni, A. Cavallini,

Semiconductor materials and devices

Abstract We report on MOCVD grown Al 1‐x In x N/AlN/GaN heterostructures with different AlN (interlayer) thicknesses, investigated by Surface Photovoltage Spectroscopy. The different contributions to SPV spectra from all the layers present within the structure have been analyzed. Below the GaN band gap SPV analysis has been performed, and the observed peaks related to red, yellow and green defect states in GaN. The density of the two dimensional electron gas (2DEG) forming at the interface has been measured. A band gap shift has been detected and its dependence on the 2DEG electron density at the AlN/GaN interface has been analyzed on the basis of the Moss Burstein and renormalization effects. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)