Enhanced performance of vertical GaN-based LEDs with a highly reflective ohmic contact and a nano-roughened indium-zinc oxide transparent conduction layer

Der-Ming Kuo; Shui-Jinn Wang; Kai-Ming Uang; Tron-Ming Chen; Wei-Chi Lee; Pei-Ren Wang

doi:10.1117/12.840170

11 February 2010 Enhanced performance of vertical GaN-based LEDs with a highly reflective ohmic contact and a nano-roughened indium-zinc oxide transparent conduction layer

Der-Ming Kuo, Shui-Jinn Wang, Kai-Ming Uang, Tron-Ming Chen, Wei-Chi Lee, Pei-Ren Wang

Author Affiliations +

Proceedings Volume 7617, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XIV; 76170Q (2010) https://doi.org/10.1117/12.840170
Event: SPIE OPTO, 2010, San Francisco, California, United States

Abstract

The use of Polystyrene Spheres (PSs) to realize nano-roughened Indium-Zinc Oxide (IZO) surface and a high reflective ohmic p-contact to improve the optoelectronic properties of larger-area (1×1 mm²) vertical metallic-substrate GaN-based light-emitting diodes (VLEDs) were proposed and investigated. A metal system consisting of annealed- Pt/Al/Pt was employed to serve as a reflector and ohmic contact to p-GaN, which exhibits a good ohmic contact (1.84×10^-3 Ωcm²) and high reflectivity (88% at 465 nm). After the removal of sapphire using laser lift-off process (LLO) and etching of u-GaN by ICP, Ti/IZO film was then deposited to serve as a transparent conduction layer (TCL). After that, the polystyrene spheres (PSs) were dispersed on the IZO surface, followed by second sputtering-deposition of IZO film to fill the space between neighboring PSs. The PSs were then removed to form a nano-roughened IZO top-layer. Compared to regular VLEDs with Ni/Au ohmic contact and Ti/Al/Ti/Au as reflector layer, the fabricated VLED shows a typical increase in light output power (i.e., ▵Lop/Lop) by 72.2% at 350 mA and a decrease in forward voltage (Vf) from 3.43 V down to 3.33 V. It is expected that the proposed PSs nano-roughening technology and high reflection annealed- Pt/Al/Pt metal system for ohmic contact to p-GaN would be a potential candidate for the fabrication of high power GaNbased LEDs for solid-state lighting in the near future.

Citation Download Citation

Der-Ming Kuo, Shui-Jinn Wang, Kai-Ming Uang, Tron-Ming Chen, Wei-Chi Lee, and Pei-Ren Wang "Enhanced performance of vertical GaN-based LEDs with a highly reflective ohmic contact and a nano-roughened indium-zinc oxide transparent conduction layer", Proc. SPIE 7617, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XIV, 76170Q (11 February 2010); https://doi.org/10.1117/12.840170

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Light emitting diodes

Reflectivity

Oxides

Metals

Electroluminescence

Optical spheres

Etching

Show All Keywords

Keywords/Phrases

Search In:

Publication Years