High Density Two-Dimensional Hole Gas Induced by Negative Polarization at GaN/AlGaN Heterointerface

Abstract
High density two dimensional hole gas (2DHG) with a charge density of 1.1×1013 cm-2 has been demonstrated for the first time in GaN/AlGaN heterostructures. The 2DHG is induced by negative polarization charges at the GaN/AlGaN interface. The layer structures have been designed based on theoretical simulation results to maximize the 2DHG charge density. The heterostructures have been grown on sapphire substrate by metal organic chemical vapor deposition. Hall mobility of the 2DHG of 16 cm2 V-1 s-1 has been measured at room temperature with sheet resistance of 35 kΩ/sq.