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

High density two dimensional hole gas (2DHG) with a charge density of $1.1\times 10^{13}$ 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 th...

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Published inApplied physics express Vol. 3; no. 12; pp. 121004 - 121004-3
Main Authors Nakajima, Akira, Sumida, Yasunobu, Dhyani, Mahesh H, Kawai, Hiroji, Narayanan, E. M. Sankara
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.12.2010
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Summary:High density two dimensional hole gas (2DHG) with a charge density of $1.1\times 10^{13}$ 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 cm 2 V -1 s -1 has been measured at room temperature with sheet resistance of 35 k$\Omega$/sq.
Bibliography:Schematics of (a) layer structure and (b) band diagram. Predicted results of 2DHG and 2DEG densities for different (a) p-GaN thicknesses and (b) AlGaN thickness at 300 K. (a) A simplified schematic of fabricated pn junction diode and (b) the $C$--$V$ measurement results with different temperature under reverse bias condition. The inserted figure shows calculated depletion width at the zero bias condition. Simulated band diagram and hole and electron distribution of the measured layer structure at 300 K.
ISSN:1882-0778
1882-0786
DOI:10.1143/APEX.3.121004