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Title: Asymmetric tunneling model of forward leakage current in GaN/InGaN light emitting diodes

Through investigating the temperature dependent current-voltage (T-I-V) properties of GaN based blue and green LEDs in this study, we propose an asymmetric tunneling model to understand the leakage current below turn-on voltage (V < 3.2 V): At the forward bias within 1.5 V ∼ 2.1 V (region 1), the leakage current is main attributed to electrons tunneling from the conduction band of n-type GaN layer to the valence band of p-type GaN layer via defect states in space-charge region (SCR); While, at the forward bias within 2 V ∼ 2.4 V (region 2), heavy holes tunneling gradually becomes dominant at low temperature (T < 200K) as long as they can overcome the energy barrier height. The tunneling barrier for heavy holes is estimated to be lower than that for electrons, indicating the heavy holes might only tunnel to the defect states. This asymmetric tunneling model shows a novel carrier transport process, which provides better understanding of the leakage characteristics and is vital for future device improvements.
Authors:
; ; ; ; ; ; ; ;  [1]
  1. Jiangsu Provincial Key Laboratory of Advanced photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing National Laboratory of Microstructures Nanjing University, Nanjing 210093 (China)
Publication Date:
OSTI Identifier:
22492320
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 8; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ELECTRONS; GALLIUM NITRIDES; HOLES; INDIUM COMPOUNDS; LAYERS; LEAKAGE CURRENT; LIGHT EMITTING DIODES; N-TYPE CONDUCTORS; P-TYPE CONDUCTORS; SPACE CHARGE; TEMPERATURE DEPENDENCE; TUNNEL EFFECT; VALENCE