T. (Tim) Senden MSc
T.Senden@uu.nl
Gegenereerd op 2017-06-23 14:11:50


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New narrow band red phosphors for w-LEDs

The white light LED (w-LED) is an interesting alternative compact light source due to its high energy efficiency and long life time. The color rendering of w-LEDs is however an issue for the home lighting market. Conventional w-LEDs are composed of a blue LED ((In,Ga)N) and a yellow-emitting phosphor (Y3Al5O12:Ce3+), which yields cool white light that is experienced as unpleasant (Fig. 1). Hence, to develop warm-white LEDs including a red component, there is a worldwide search for a red-emitting material which is excitable in the blue and emits a narrow band around 610-620 nm (red). The narrow band is important as the eye sensitivity drops above 630 nm.

In this project we will investigate several new interesting strategies to develop a narrow band red phosphor. The first strategy focuses on the use of the Eu2+ 4f65d→ 4f7 emission, which normally has a broad spectral bandwidth (>50 nm). However, recently unusual narrow band red emission of Eu2+ was reported [1]. In this project we will systematically research the origin of this narrow band emission and later use it to develop a new narrow band red Eu2+ phosphor.

The second strategy is based on Eu3+ luminescence. Eu3+ is the ideal narrow band red emitter for w-LEDs, with its narrow 5D7F1,2 f-f emission lines in the 580-620 nm spectral region. The problem is however the sensitization of the Eu3+ emission in the blue spectral region. Therefore we are investigating several novel methods to sensitize Eu3+ emission.

The last strategy relies on red emission by Mn4+. The narrow 2E → 4A2 d-d emission band of Mn4+ usually lies between 630 and 670 nm, emitting at longer wavelengths for an increasing covalency of the host lattice. It will be studied if a shift of the Mn4+ emission to shorter wavelengths (610-620 nm) can be obtained by incorporating Mn4+ in highly ionic compounds (low covalency).

[1] A.M. Srivastava et al.J. Lumin. 129, 919-925 (2009).

Gegenereerd op 2017-06-23 14:11:50
All publications
  2016 - Scholarly publications
Mattera, Lucia, Bhuckory, Shashi, Wegner, K. David, Qiu, Xue, Agnese, Fabio, Lincheneau, Christophe, Senden, Tim, Djurado, David, Charbonnière, Loïc J., Hildebrandt, Niko & Reiss, Peter (07.06.2016). Compact quantum dot-antibody conjugates for FRET immunoassays with subnanomolar detection limits. Nanoscale, 8 (21), (pp. 11275-11283) (9 p.).
Senden, T., Broers, Fréderique & Meijerink, A. (2016). Comparative study of the Mn4+ 2E → 4A2 luminescence in isostructural RE2Sn2O7:Mn4+ pyrochlores (RE3+ = Y3+, Lu3+ or Gd3+). Optical Materials, 60, (pp. 431-437) (7 p.).
Senden, Tim & Meijerink, A (2016). The d-f luminescence of Eu2+, Ce3+ and Yb2+ ions in Cs2MP2O7 (M = Ca2+, Sr2+). Journal of Luminescence, 177, (pp. 254-260) (7 p.).
  2015 - Scholarly publications
Senden, Tim, Rabouw, Freddy & Meijerink, A (13.01.2015). Photonic Effects on the Radiative Decay Rate and Luminescence Quantum Yield of Doped Nanocrystals. ACS Nano, 9 (2), (pp. 1801-1808).
  2014 - Scholarly publications
Rabouw, Freddy T., Den Hartog, Stephan A., Senden, Tim & Meijerink, A (02.04.2014). Photonic effects on the Förster resonance energy transfer efficiency. Nature Communications, 5.
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Gegenereerd op 2017-06-23 14:11:50
Full name
T. Senden MSc Contact details
Leonard S. Ornsteinlaboratorium

Princetonplein 1
Room 168
3584 CC  UTRECHT
The Netherlands


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Gegenereerd op 2017-06-23 14:11:50
Last updated 15.09.2016