Implementation of high-quality warm-white light-emitting diodes by a model-experimental feedback approach using quantum dot-salt mixed crystals

buir.contributor.orcidDemir, Hilmi Volkan|0000-0003-1793-112Xen_US
dc.contributor.authorAdam, M.en_US
dc.contributor.authorErdem, T.en_US
dc.contributor.authorStachowski, G.M.en_US
dc.contributor.authorSoran-Erdem Z.en_US
dc.contributor.authorLox, J. F. L.en_US
dc.contributor.authorBauer, C.en_US
dc.contributor.authorPoppe, J.en_US
dc.contributor.authorDemir, Hilmi Volkanen_US
dc.contributor.authorGaponik N.en_US
dc.contributor.authorEychmüller A.en_US
dc.contributor.bilkentauthorDemir, Hilmi Volkan
dc.departmentDepartment of Electrical and Electronics Engineeringen_US
dc.departmentDepartment of Physicsen_US
dc.departmentInstitute of Materials Science and Nanotechnology (UNAM)en_US
dc.description.abstractIn this work, a model-experimental feedback approach is developed and applied to fabricate high-quality, warm-white light-emitting diodes based on quantum dots (QDs) as color-conversion materials. Owing to their unique chemical and physical properties, QDs offer huge potential for lighting applications. Nevertheless, both emission stability and processability of the QDs are limited upon usage from solution. Incorporating them into a solid ionic matrix overcomes both of these drawbacks, while preserving the initial optical properties. Here borax (Na2B4O7·10H2O) is used as a host matrix because of its lower solubility and thereby reduced ionic strength in water in comparison with NaCl. This guarantees the stability of high-quality CdSe/ZnS QDs in the aqueous phase during crystallization and results in a 3.4 times higher loading amount of QDs within the borax crystals compared to NaCl. All steps from the synthesis via mixed crystal preparation to the warm-white LED preparation are verified by applying the model-experimental feedback, in which experimental data and numerical results provide feedback to each other recursively. These measures are taken to ensure a high luminous efficacy of optical radiation (LER) and a high color rendering index (CRI) of the final device as well as a correlated color temperature (CCT) comparable to an incandescent bulb. By doing so, a warm-white LED with a LER of 341 lm/Wopt, a CCT of 2720 K and a CRI of 91.1 is produced. Finally, we show that the emission stability of the QDs within the borax crystals on LEDs driven at high currents is significantly improved. These findings indicate that the proposed warm-white light-emitting diodes based on QDs-in-borax hold great promise for quality lighting. © 2015 American Chemical Society.en_US
dc.publisherAmerican Chemical Societyen_US
dc.source.titleACS Applied Materials and Interfacesen_US
dc.subjectColloidal nanocrystalsen_US
dc.subjectColor conversionen_US
dc.subjectMixed crystalsen_US
dc.subjectQuantum dotsen_US
dc.subjectWhite LEDsen_US
dc.subjectBorate mineralsen_US
dc.subjectComposite materialsen_US
dc.subjectIonic strengthen_US
dc.subjectOptical propertiesen_US
dc.subjectSemiconductor quantum dotsen_US
dc.subjectSodium borateen_US
dc.subjectChemical and physical propertiesen_US
dc.subjectColloidal nanocrystalsen_US
dc.subjectColor conversionsen_US
dc.subjectCorrelated color temperatureen_US
dc.subjectHigh color rendering indexen_US
dc.subjectMixed crystalsen_US
dc.subjectWhite LEDen_US
dc.subjectWhite light emitting diodesen_US
dc.subjectLight emitting diodesen_US
dc.titleImplementation of high-quality warm-white light-emitting diodes by a model-experimental feedback approach using quantum dot-salt mixed crystalsen_US
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Implementation of High-Quality Warm-White Light-Emitting Diodes by a Model-Experimental Feedback Approach Using Quantum Dot–Salt Mixed Crystals.pdf
7.28 MB
Adobe Portable Document Format
Full printable version