skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Final Technical Report

Abstract

To push the boundaries of efficiency and cost in solid state lighting (SSL), narrow band red emitting down conversion phosphors must be improved. These materials are critical to both the color rendering ability and optical output of phosphor converted light emitting diodes (LEDs). Improvements in these performance parameters will have a significant impact on the adoption of SSL in retail, office, and home lighting applications. Quantum Dots (QDs) are widely acknowledged as a cost-effective front-runner among developing downconverting technologies because they emit narrow band luminescence that is tunable across the visible spectrum. Current syntheses of quantum dots, however, utilize expensive and toxic reagents and often involve several time-intensive purification steps. To address this, we have introduced a novel, cost-effective synthetic scheme, whereby the final quantum dot structures can be accessed with fewer synthetic steps using a library of inexpensive, easily-synthesized precursors. With the help of automated high throughput synthesis robotics, Columbia, LBNL, and OSRAM have optimized red and amber CdS/CdSe/CdS QD architectures for SSL. QDs with improved shelling layers have been identified that meet the industry state of the art performance on chip under high humidity accelerated aging tests. This is remarkable considering the time frame of this project comparedmore » to the time and resources allocated for the development of the industrial standard. Furthermore, although particle stability to optical charging is often stressed in improving QLED performance, we have identified effective ZnS particle over-coating as the most important factor determining particle survivability and device performance in down-converting LEDs.« less

Authors:
ORCiD logo [1]
  1. Columbia Univ., New York, NY (United States)
Publication Date:
Research Org.:
Columbia University
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B)
OSTI Identifier:
1491009
Report Number(s):
DOE-ColumbiaUniversity-7628
DOE Contract Number:  
EE0007628
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; nanocrystal; quantum dot; solid state lighting; SSL; light emitting diode; phosphor; down conversion

Citation Formats

Owen, Jonathan S. Final Technical Report. United States: N. p., 2018. Web. doi:10.2172/1491009.
Owen, Jonathan S. Final Technical Report. United States. doi:10.2172/1491009.
Owen, Jonathan S. Thu . "Final Technical Report". United States. doi:10.2172/1491009. https://www.osti.gov/servlets/purl/1491009.
@article{osti_1491009,
title = {Final Technical Report},
author = {Owen, Jonathan S.},
abstractNote = {To push the boundaries of efficiency and cost in solid state lighting (SSL), narrow band red emitting down conversion phosphors must be improved. These materials are critical to both the color rendering ability and optical output of phosphor converted light emitting diodes (LEDs). Improvements in these performance parameters will have a significant impact on the adoption of SSL in retail, office, and home lighting applications. Quantum Dots (QDs) are widely acknowledged as a cost-effective front-runner among developing downconverting technologies because they emit narrow band luminescence that is tunable across the visible spectrum. Current syntheses of quantum dots, however, utilize expensive and toxic reagents and often involve several time-intensive purification steps. To address this, we have introduced a novel, cost-effective synthetic scheme, whereby the final quantum dot structures can be accessed with fewer synthetic steps using a library of inexpensive, easily-synthesized precursors. With the help of automated high throughput synthesis robotics, Columbia, LBNL, and OSRAM have optimized red and amber CdS/CdSe/CdS QD architectures for SSL. QDs with improved shelling layers have been identified that meet the industry state of the art performance on chip under high humidity accelerated aging tests. This is remarkable considering the time frame of this project compared to the time and resources allocated for the development of the industrial standard. Furthermore, although particle stability to optical charging is often stressed in improving QLED performance, we have identified effective ZnS particle over-coating as the most important factor determining particle survivability and device performance in down-converting LEDs.},
doi = {10.2172/1491009},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2018},
month = {11}
}