Engineering Spontaneous Emission in Hybrid Nanoscale Materials for Optoelectronics and Bio-photonics
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Engineering Spontaneous Emission in Hybrid Nanoscale Materials for Optoelectronics and Bio-photonics. Arup Neogi Department of Physics and Materials Engineering University of North Texas Email: [email protected] Research Areas. http://www.phys.unt.edu/research/photonic/website/.

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Engineering Spontaneous Emission in Hybrid Nanoscale Materials for Optoelectronics and Bio-photonics

Arup Neogi

Department of Physics and Materials Engineering

University of North Texas

Email: [email protected]


Ultrafast and nanoscale photonics group arup neogi department of physics

Research Areas Materials for Optoelectronics and Bio-photonics

http://www.phys.unt.edu/research/photonic/website/

  • Nanoscale Optoelectronic materials for efficient light emission

  • Biophotonic materials; for hybrid molecular electronics and photonics

Ultrafast and Nanoscale Photonics GroupArup Neogi, Department of Physics

  • Funding:

  • National Science Foundation

  • US Department of Energy

  • Japan Soc. for Promotion of Sciences


Surface plasmons polariton coupling with directional emission
Surface plasmons polariton coupling with directional emission

  • Using subwavelength corrugated surface grating:

  • Momentum can be transferred to couple the light and plasmon modes

  • Directional Emission can be improved by using corrugated surfaces


Change in radiative recombination lifetime in Qdots due to resonant exciton-surface plasmon coupling

Radiative recombination rate in strained quantum dots emission - observed above the SP emission energy


Energy transfer in quantum dots entrapped in hydrogel microspheres

Energy Transfer in Quantum Dots entrapped in Hydrogel Microspheres

Arup Neogi, Zhibing Hu

Department of Physics

University of North Texas


Temperature induced changes in hydrogel

1 cm Microspheres

1 cm

21 oC

35 oC

The NIPAM sample in water: Effect of temperature61

Temperature induced changes in hydrogel

The phase transition temperature (Tc) of PNIPAM is 34 °C. below Tc, the hydrogel is hydrophilic and swells in water, while above Tc it is hydrophobic and collapses into a small volume.


Change in scattering properties with particle size
Change in scattering properties with particle size Microspheres

Variation of Particle size with chemistry

Change in scattering properties with turbidity


Photoluminescence spectrum of qds embedded in gel

UV Microspheres

Sunlight

The PL image of PNIPAM/CdTe microgel under UV lamp.

The image of PNIPAM/CdTe microgel under sunlight

Photoluminescence Spectrum of QDs embedded in GEL


Electric field induced effects in pnipa gels
Electric Field Induced effects in PNIPA Gels Microspheres

At room temperature

No electric field

3.5V/cm electric field

*Wu, J. et. al. Phys. Rev. Lett., 90, 48304 (2003)

+Hu, Z. et. al. Advan. Mater.13, 1708 (2001)


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