Energy-saving quality road lighting with colloidal quantum dot nanophosphors

Erdem, Talha
Keleştemur, Yusuf
Ji, Yun
Demir, Hilmi Volkan
Here the first photometric study of road-lighting white light-emitting diodes (WLEDs) integrated with semiconductor colloidal quantum dots (QDs) is reported enabling higher luminance than conventional light sources, specifically in mesopic vision regimes essential to street lighting. Investigating over 100 million designs uncovers that quality road-lighting QD-WLEDs, with a color quality scale and color rendering index >= 85, enables 13-35% higher mesopic luminance than the sources commonly used in street lighting. Furthermore, these QD-WLEDs were shown to be electrically more efficient than conventional sources with power conversion efficiencies >= 16-29%. Considering this fact, an experimental proof-of-concept QD-WLED was demonstrated, which is the first account of QD based color conversion custom designed for street lighting applications. The obtained white LED achieved the targeted mesopic luminance levels in accordance with the road lighting standards of the USA and the UK. These results indicate that road-lighting QD-WLEDs are strongly promising for energy-saving quality road lighting.


Pulsed optically stimulated luminescence from α-Al2O3:C using green light emitting diodes
Bulur, Enver (1997-01-01)
Optically Stimulated Luminescence (OSL) from alpha-Al2O3:C was investigated using green light emitting diodes (LED) for excitation. Time resolved luminescence characteristics of the samples were studied by pulsing the LEDs during the readout. The effects of excitation light intensity, pulse width and readout temperature on the OSL signal were investigated. The radiation dose response of the dosimeters with above mentioned parameters was also evaluated for the applicability to radiation dosimetry.
Magnetic Fe3O4-chitosan micro- and nanoparticles for wastewater treatment
ŞAHBAZ, DENİZ AKIN; YAKAR, ARZU; Gündüz, Ufuk (2019-08-18)
In this study, first, magnetic nanoparticles (MNP) were synthesized using a coprecipitation method and the synthesized particles were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and vibrating sample magnetometry (VSM). According to DLS and VSM analyses results, it was seen that the size of the MNP was smaller than 10 nm and they exhibited superparamagnetic properties, respectively. Then, magnetic Fe3O4-chitosan micro/n...
Nano-scale phase separation and glass forming ability of iron-boron based metallic glasses
Aykol, Muratahan; Akdeniz, Mahmut Vedat; Department of Metallurgical and Materials Engineering (2008)
This study is pertinent to setting a connection between glass forming ability (GFA) and topology of Fe-B based metallic glasses by combining intimate investigations on spatial atomic arrangements conducted via solid computer simulations with experimentations on high GFA bulk metallic glasses. In order to construct a theoretical framework, the nano-scale phase separation encountered in metallic glasses is investigated for amorphous Fe80B20 and Fe83B17 alloys via Monte Carlo equilibration and reverse Monte Ca...
High-efficiency high-quality street lighting with colloidal quantum dot nanophosphors
ERDEM, TALHA; Keleştemur, Yusuf; Soran-Erdem, Zeliha; Ji, Yun; Demir, Hilmi Volkan (2015-01-01)
We present the fIrst photometric study of white light-emitting diodes (WLEDs) employing colloidal quantum dots specifically for street lighting. These WLEDs exhibit the largest mesopic luminance 35% higher than conventional sources, consuming 29% less energy.
Frequency Selective Characteristics of a Plasma Layer with Sinusoidally Varying Electron Density Profile
GÜREL, ÇİĞDEM SEÇKİN; Oencue, Emrah (Springer Science and Business Media LLC, 2009-06-01)
In this study reflection, absorbtion and transmission characteristics of a plasma layer having sinusoidally varying electron number density are analysed. In the analysis, plasma layer is divided into thin subslabs with constant electron number densities. The general frequency selective behavior of the plasma is investigated by varying the plasma parameters, external magnetic field excitation and sinusoidal electron distribution in order to be used in recent plasma applications.
Citation Formats
T. Erdem, Y. Keleştemur, Z. SORAN ERDEM, Y. Ji, and H. V. Demir, “Energy-saving quality road lighting with colloidal quantum dot nanophosphors,” NANOPHOTONICS, vol. 3, no. 6, pp. 373–381, 2014, Accessed: 00, 2021. [Online]. Available: