A charge inverter for III-nitride light-emitting diodes
Date
2016Source Title
Applied Physics Letters
Print ISSN
0003-6951
Publisher
American Institute of Physics Inc.
Volume
108
Issue
13
Pages
133502-1 - 133502-5
Language
English
Type
ArticleItem Usage Stats
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Abstract
In this work, we propose a charge inverter that substantially increases the hole injection efficiency for InGaN/GaN light-emitting diodes (LEDs). The charge inverter consists of a metal/electrode, an insulator, and a semiconductor, making an Electrode-Insulator-Semiconductor (EIS) structure, which is formed by depositing an extremely thin SiO2 insulator layer on the p+-GaN surface of a LED structure before growing the p-electrode. When the LED is forward-biased, a weak inversion layer can be obtained at the interface between the p+-GaN and SiO2 insulator. The weak inversion region can shorten the carrier tunnel distance. Meanwhile, the smaller dielectric constant of the thin SiO2 layer increases the local electric field within the tunnel region, and this is effective in promoting the hole transport from the p-electrode into the p+-GaN layer. Due to the improved hole injection, the external quantum efficiency is increased by 20% at 20 mA for the 350 × 350 μm2 LED chip. Thus, the proposed EIS holds great promise for high efficiency LEDs.
Keywords
Charge injectionEfficiency
Electric fields
Electric inverters
Electrodes
Electron injection
Gallium nitride
Semiconductor diodes
Wide band gap semiconductors
External quantum efficiency
High-efficiency
Hole transports
Improved hole injection
Ingan/gan lightemitting diodes (LEDs)
Insulator layer
Local electric field
Weak inversion region
Light emitting diodes