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Indexed by:期刊论文

Date of Publication:2013-12-01

Journal:MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING

Included Journals:SCIE、EI、Scopus

Volume:16

Issue:6

Page Number:1684-1687

ISSN No.:1369-8001

Key Words:Zinc oxide; Gallium nitride; Zinc magnesium oxide; Heterostructure; Ultrasonic spray pyrolysis; Tunneling

Abstract:The heterojunction diodes with n-ZnO/ZnMgO/p-GaN structure have been deposited on the commercially available p-GaN/sapphire substrates by a simple process of ultrasonic spray pyrolysis. To demonstrate the effect of ZnMgO layer as electron blocking layer, the carrier transport mechanisms of both n-ZnO/p-GaN and n-ZnO/ZnMgO/p-GaN heterojunctions were systemically investigated by temperature-dependent current voltage measurements. The results revealed that the multistep tunneling is the dominant carrier transport mechanism in n-ZnO/ZnMgO/p-GaN heterojunctions under forward current, accurately controlled ZnMgO layer thickness can effectively block electron injection from ZnO to GaN and promote hole injection from GaN to ZnO. Therefore, the design and application of ZnO based heterostructure devices will benefit significantly from these achievements. (C) 2013 Elsevier Ltd. All rights reserved.