Blue/UV LEDs with Very High Photon Conversion and Extraction Efficiency for White Lighting
Investigating Organization
Boston University
Principal Investigator(s)
Professor Theodore Moustakas
Subcontractor
SAIC - Spilios Riyopolous
Funding Source
Building Technologies Program/NETL
Award
DOE Share: $959,993; Contractor Share: $242,700
Contract Period
09/24/04 - 11/30/07
This project is studying a unique approach to growing GaN-based LEDs on thick textured GaN quasi-substrates, using Hydride Vapor Phase Epitaxy (HVPE) instead of more costly Metal-Organic Chemical Vapor Deposition (MOCVD). It is anticipated that the work will demonstrate vastly improved device efficiencies. This is due to the substantial reduction in defect densities normally associated with nitride devices grown on materials of differing lattice constants, such as sapphire. In addition to exploring the potential for large increases in internal quantum efficiency due to the defect density reduction, significant increases in external quantum efficiencies are also possible due to the reduction in natural wave guiding that generally occurs at material interfaces. This imaginative work will address a number of issues plaguing the performance of nitride systems and may enable future breakthroughs in device efficiency and light management.