Silicon nanoparticles: Absorption, emission and the nature of the electronic bandgap

In: Journal of Applied Physics, Jg. 101 (2007) ; Nr. 10, S. 103112 (8pp)
ISSN: 0021-8979
Zeitschriftenaufsatz / Fach: Maschinenbau; Physik
Fakultät für Physik » Experimentalphysik
Siliconnanoparticles synthesized in the gas phase are studied. From time-resolved photoluminescence measurements we determine, quantitatively, the size-dependence of the oscillator strength of the nanoparticles. We investigate experimentally the absorption and photoluminescence emission of nanoparticle ensembles with a broad size distribution. Using a model which accounts for size-effects in both oscillator strength and quantum-confinement, we are able to calculate absorption and emission spectra of ensemble samples. From these results we have determined, whether siliconnanoparticles should be regarded as indirect or direct semiconductors. Moreover, we systematically study the influence of the particle size-distribution on the optical spectra.