Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 20: Photonische Kristalle IV

HL 20.1: Vortrag

Dienstag, 9. März 2004, 15:15–15:30, H17

Optical characterisation of opal heterojunctions — •Sergei Romanov¹, Dmitry Chigrin¹, Vladimir Solovyev¹, Clivia Sotomayor Torres¹, Nikolai Gaponik², Alexander Eychmueller², and Andrei Rogach³ — ¹Inst. of Materials Science and Dept. of Electrical and Information Engineering, University of Wuppertal, 42097, Germany — ²Inst. of Physical Chemistry, University of Hamburg, 20146, Germany — ³Dept. of Physics, University of Munich, 80799, Germany

Interfacing of photonic crystals (PhCs) is a step towards their functionalisation. The anticipated effects are engineered PBG, light confinement and directing of the light flow. Hetero-opals were prepared by sandwiching two thin film opals assembled from latex beads of different diameters, while staying with preparation by self-assembly. Angle-resolved reflectance, transmission, scattering and emission of light were used to characterise hetero-opals.

Anomalous transmission minimum was observed in between two Bragg gaps of the hetero-opal constituents and associated with the interface. This observation was supplemented by reflectance and scattering experiments. Finite difference time domain modelling of light propagation in 2D PhC hetero-junction was used to study this effect.

Anomalies of emission spectra of CdTe nanoparticles embedded in hetero-opals, which were observed at frequencies of the interface gap, agree the interface gap model.