Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 64: Quantum Dots and Wires: Optical Properties VI
HL 64.10: Vortrag
Freitag, 26. März 2010, 12:45–13:00, H14
Electroluminescence from silicon nanoparticles — •Jens Theis1, Cedrik Meier2, Axel Lorke1, and Hartmut Wiggers3 — 1Experimental Physics and CeNIDE, University of Duisburg-Essen — 2Nanophotonics & Nanomaterials Group, University Paderborn — 3Institute of Combustion and Gas Dynamics and CeNIDE, University of Duisburg-Essen
We have fabricated an electroluminescence device based on silicon nanoparticles on a micropatterned GaAs heterostructure. The Si nanoparticles have been synthesized from the gas phase in a low-pressure microwave plasma using SiH4 as a precursor. The nanoparticles were dispersed from an aqueous solution onto the patterned GaAs sample. For carrier injection, the particle layer was incorporated into a capacitor-like structure, where a transparent ITO layer served as the top-electrode. An AC-voltage accelerates electrons from the top gate to the GaAs-back contact. These electrons generate secondary electrons and holes by impact ionization and thus induce electron-hole pair recombination in the nanoparticles. For further analysis an optical, high resolution two-dimensional scans of the electroluminescence device was performed in a µ-Photoluminescence setup. Additionally, we study the influence that waveform, frequency and amplitude of the AC voltage on the electroluminescence. PL measurements made on separate samples of the same nanoparticles were also conducted. As a result, we conclude that the electroluminescence light around 700 nm and around 850 nm arise from the nanoparticles and the GaAs substrate, respectively.