Quantum efficiency enhancement in nanocrystals using nonradiative energy transfer with optimized donor-acceptor ratio for hybrid LEDs

Nizamoglu, Sedat; Akin, Onur; Demir, Hilmi Volkan
June 2009
Applied Physics Letters;6/15/2009, Vol. 94 Issue 24, p243107
Academic Journal
The quantum efficiency enhancement in nanocrystal solids is critically important for their efficient use as luminophors on color-conversion light emitting diodes (LEDs). For this purpose, we investigate energy gradient mixture of nanocrystal solids for recycling their trapped excitons by varying their donor-acceptor nanocrystal ratios and study the resulting quantum efficiency enhancement as a function of the donor-acceptor ratio in the solid film for hybrid LEDs. We achieve a maximum quantum efficiency enhancement of 17% in these nanocrystal solids when the donor-acceptor ratio is 1:1, demonstrating their highly modified time-resolved photoluminescence decays to reveal the kinetics of strong energy transfer between them.


Related Articles

  • Efficiency retention at high current injection levels in m-plane InGaN light emitting diodes. Li, X.; Ni, X.; Lee, J.; Wu, M.; Özgür, Ü.; Morkoç, H.; Paskova, T.; Mulholland, G.; Evans, K. R. // Applied Physics Letters;9/21/2009, Vol. 95 Issue 12, p121107 

    We investigated the internal quantum efficiency (IQE) and the relative external quantum efficiency (EQE) of m-plane InGaN light emitting diodes (LEDs) grown on m-plane freestanding GaN emitting at ∼400 nm for current densities up to 2500 A/cm2. IQE values extracted from intensity and...

  • Enhanced luminescence of Y3Al5O12:Ce3+ nanophosphor for white light-emitting diodes. Haranath, D.; Chander, Harish; Sharma, Pooja; Singh, Sukhvir // Applied Physics Letters;10/23/2006, Vol. 89 Issue 17, p173118 

    Results pertaining to the development of highly dispersible stand-alone particles of Ce3+-doped Y3Al5O12 nanophosphor and their luminescence are presented. The yellow light-emitting nanophosphor was produced as a result of a single-step auto-combustion process, which requires no auxiliary...

  • Room temperature ultraviolet emission at 357 nm from polysilane based organic light emitting diode. Sharma, Asha; Katiyar, Monica; Shu Seki; Tagawa, Seiichi // Applied Physics Letters;4/3/2006, Vol. 88 Issue 14, p143511 

    We have fabricated an organic light emitting diode using poly(n-butylphenylsilane) which has an emission in deep ultraviolet at 357 nm at room temperature. The device structure used is glass/indium tin oxide/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)/polysilane (emitting...

  • Roll-coating organic LED is first step to cheaper fabrication. Carts-Powell, Yvonne // Laser Focus World;Jun2004, Vol. 40 Issue 6, p38 

    Reports on Richland, Washington-based Pacific Northwest Laboratory researchers' demonstration of a method for depositing a film of the active layer of small-molecule organic light emitting diodes onto a flexible plastic substrate. Advantages of Pacific's method over traditional approaches;...

  • Use an LED to sense and emit light. Camarota, Rafael // EDN Europe;Jun2009, Vol. 56 Issue 6, p26 

    The article focuses on the performance and circuit behavior of light-emitting diodes (LEDs). It notes that LEDs ascertain the battery life of any electronic device. It mentions several ways in decreasing the power use of LED, which include the increase of its flash duration, reduction of its...

  • Opinion: The status quo of changes in colour rendering indices. Luo, M. Ronnier // Lighting Research & Technology;Dec2012, Vol. 44 Issue 4, p384 

    The author discusses aspects of light sources. He states that TC was established because CIE-R uses outdated colorimetric tools and underestimates the rendering ability of light emitting diode (LED) solid-state light sources. He mentions that a color discrimination index allows users to have a...

  • Rolling out flexible screen technology.  // Industrial Engineer: IE;Apr2004, Vol. 36 Issue 4, p17 

    Focuses on the construction of a flexible organic light-emitting device in a research by engineers at the University of Toronto. Contribution of the technology to the future development of bendable television, computer and cell phone screens.

  • Microspere-doped acrylic rods mix colors. Overton, Gail // Laser Focus World;Oct2004, Vol. 40 Issue 10, p17 

    Reports that researchers at the University of Technology Sydney Department of Applied Physics in Sydney, New South Wales, have used doped acrylic rods to color-mix light emitting diodes (LEDs). Common methods used to produce white light for illumination from LEDs; Disadvantage of undoped light...

  • Measurement of the absorption coefficient for light laterally propagating in light-emitting diode structures with In0.2Ga0.8N/GaN quantum wells. Lelikov, Yu. S.; Bochkareva, N. I.; Gorbunov, R. I.; Martynov, I. A.; Rebane, Yu. T.; Tarkin, D. V.; Shreter, Yu. G. // Semiconductors;Nov2008, Vol. 42 Issue 11, p1342 

    A procedure for measuring the absorption coefficient for light propagating parallel to the surface of a GaN-based light emitting diode chip on a sapphire substrate is suggested. The procedure implies the study of emission from one end face of the chip as the opposite end face is illuminated with...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics