A charge inverter for III-nitride light-emitting diodes
Demir, Hilmi Volkan
Sun, Xiao Wei
Date of Issue2016
School of Electrical and Electronic Engineering
LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays
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 SiO2insulator 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 SiO2insulator. 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 μm2LED chip. Thus, the proposed EIS holds great promise for high efficiency LEDs.
Light emitting diodes
Applied Physics Letters
© 2016 AIP Publishing LLC. This paper was published in Applied Physics Letters and is made available as an electronic reprint (preprint) with permission of AIP Publishing LLC. The published version is available at: [http://dx.doi.org/10.1063/1.4945257]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.