Novel porous InGaN-based hetero-nanostructures for next-generation high-performance warm white light LEDs
Abstract
We are aiming to develop a technology that will certainly attract industry related to phosphor and LED production. Environmentally benign techniques are used in combination with a one-step approach that both will contribute to better energy-efficient technologies – an ever more important issue in global economy. The resulting new designs of an unencapsulated LED structures shall be specified by superior efficiencies and is expected to be producible by a reduced number of process steps
Description of Projectidea
Objectives
We propose to fabricate an unencapsulated high-light-extraction-efficiency warm white LED based on a quasi-aligned nanoporous structure that penetrates through the entire device, and is coated with nanophosphors with luminescence properties enhanced through resonance effects with surface metallic plasmons. This high performance LED will be based on nanoporous InGaN. The nanoporous structure is generated during the growth process of the single-crystalline InGaN particles. Post-growth treatment is not needed, to allow the pores to penetrate through the entire device, quite in contrast to other approaches used up to now.
A LED fabricated in this way will benefit at least from the advantages demonstrated for LEDs coated with disordered porous structures (Liu et al., APL 94, 143502, 2009), and partially benefits from the enhancement of light extraction efficiency demonstrated for surface and bottom photonic crystals generated on LEDs as the array of nanopores can act as a photonic crystal. Phosphor nanoparticles deposited inside the pores will also be a medium with intermediate refractive index that will further enhance light extraction. Finally, brightness of the white light will be enhanced by improvement of the generated emissions by resonance effects with the surface plasmons generated by metallic nanoparticles mixed with the nanophosphors.
This project aims at demonstration of a new generation of unencapsulated high-performance warm white LEDs. Porous ZnO/InGaN hetero-nanostructures will be used. The technology developed shall be of high interest to industry due to reduced costs for processing compared to currently used technologies.
A research program with following milestones will be conducted:
(I) Growth of novel porous p-type InGaN particles aligned on n-type ZnO substrates.
(II) Deposition of n-type ZnO nanofilm onto the novel porous p-type InGaN particles.
(III) Designing phosphor materials with high electro-conductivity and luminescence efficiency.
(IV) Design and attach to the InGaN and ZnO/InGaN particles appropriate nanophosphors and metallic plasmons to finally show a prototype of an unencapsulated nano-LED structure with warm white light emission.
Consortium of partners, already existing
1 Universitat Rovira i Virgili ( EMaS Research Center) - coordinator
2 University of Cambridge
3 Università degli Studi di Verona
4 Universidad Politécnica de Madrid (ISOM)
5 AIXTRON (Commercial Enterprise)
6 Institut Néel (CNRS-Grenoble)
7 University of Crete
8 University of Sherbrooke - Centre de recherche en nanofabrication et nanocaratérisation
New partner searched to complete the consortium (competences/expertise)
- Rresearch groups in the filed of plasmonics to study and perform the depsoiton
process of metallic and/or phosphor nanoparticles in the porous.
- Industries in EU countries and Associated countries to preform the design and development of the LED test structures and its charaterization.
Topics
NMP-2011-2.2-3:
Materials for solid state lighting - SMALL
Contact
Dr. Isabel Parreu Alberich
EMaS Research Center - Rovira i Virgili University
Marcel·lí Domingo
43007 Tarragona
Homepage: http://www.urv.cat/centres_recerca/emas/en/index.html
Email: isabel.parreu@urv.cat
Phone: +34 977 558 444
Organisation: Research Organization
Responsible NCP
Dr. Mª Pilar de Miguel
Centre for the Development of Industrial Technology (CDTI)
demiguel_mpilar@cdti.es
Telephone:+34915815500
Spain
