Investigation of low-temperature electrical conduction mechanisms in highly resistive GaN bulk layers extracted with Simple Parallel Conduction Extraction Method

Date
2009-12-03
Advisor
Instructor
Source Title
Applied Physics A: Materials Science and Processing
Print ISSN
0947-8396
Electronic ISSN
Publisher
Springer
Volume
98
Issue
3
Pages
557 - 563
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

The electrical conduction mechanisms in various highly resistive GaN layers of Al x Ga1-x N/AlN/GaN/AlN heterostructures are investigated in a temperature range between T=40 K and 185 K. Temperature-dependent conductivities of the bulk GaN layers are extracted from Hall measurements with implementing simple parallel conduction extraction method (SPCEM). It is observed that the resistivity (ρ) increases with decreasing carrier density in the insulating side of the metal-insulator transition for highly resistive GaN layers. Then the conduction mechanism of highly resistive GaN layers changes from an activated conduction to variable range hopping conduction (VRH). In the studied temperature range, ln∈(ρ) is proportional to T -1/4 for the insulating sample and proportional to T -1/2 for the more highly insulating sample, indicating that the transport mechanism is due to VRH.

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Keywords
Carrier density, Conduction Mechanism, Electrical conduction mechanisms, Extraction method, GaN layers, Hall measurements, Heterostructures, Low temperatures, Parallel conduction, Temperature range, Temperature-dependent conductivity, Transport mechanism, Variable-range-hopping conductions, Gallium alloys, Insulation, Metal insulator boundaries, Metal insulator transition, Metal recovery, Semiconductor insulator boundaries, Smelting, Gallium nitride
Citation
Published Version (Please cite this version)