Browsing by Subject "Hybrid power systems"

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    Warm white light generating nanocrystal hybridized LEDs with high color rendering index
    (IEEE, 2008-11) Demir, Hilmi Volkan; Nizamoğlu, Sedat; Zengin, Güliş
    By hybridizing custom-design CdSe/ZnS core-shell NC emitters on InGaN/GaN based blue LEDs, we demonstrated three warm-white light sources with desirably low CCT ranging from 3227 K to 1982 K as is required for SSL indoor applications. In these proof-of-concept demonstrations, high color rendering indices (82.4) and high luminous efficacies of emitted spectra (327 lm/W) were achieved, while the color temperature was simultaneously kept low as desired. Our proof-of-concept demonstrations indicated that such nanocrystal luminophor based warm-white LEDs with high-quality photometric properties hold great promise especially for future indoor lighting applications.
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    ItemOpen Access
    White CdS nanoluminophore based tunable hybrid light emitting diodes
    (IEEE, 2007) Nizamoğlu, Sedat; Mutlugün, Evren; Akyüz, Özgün; Kosku-Perkgöz, Nihan; Demir, Hilmi Volkan; Liebscher, L.; Sapra, S.; Gaponik, N.; Eychmüller, A.
    The study aims to fabricate and demonstrate hybrid white light emitting diodes that integrate white emitting CdS nanoluminophores with high light quality. Results show that the white light properties of these hybrid WLED (including (x,y) chromaticity coordinates, color temperature, and color rendering index (Ra)) are conveniently tuned as desired across the white region by controlling the number of these surface state emitting nanoluminophores hybridized on the n-UV LED platform. In this tuning process, with the increasing number of the hybridized surface state emitting nanocrystals, it is observed that (x,y) and Ra increase while Tc decreases.