Optical properties of II-VI colloidal quantum dot doped porous silicon microcavities

Abstract

In this paper we report on the light emitting properties of mesoporous silicon vertical-cavity optical resonators with II-VI colloidal quantum dots selectively deposited in the cavity layer. Optical resonator structures exhibit reflectivity stop bands of several hundred nanometres and resonant modes with line-widths less than 3.5 nm. The observed modification of spectral and spatial emission properties of the quantum dots and tenfold enhancement at the resonance wavelength is consistent with cavity enhanced spontaneous emission. Using this hybrid fabrication approach we show that narrow band light emitting structures may be fabricated over a broad spectral region in the visible and near-infrared.

Mixing rules and the Casimir force between composite systems

“…Besides the Maxwell-Garnett and the Bruggeman EMA we selected Looyenga's approach [48], which is in good agreement with experimental measurements of the effective optical properties of colloidal quantum dot systems [49]. Looyenga's model for spherical inclusions assumes an equation for the effective dielectric function of the form…”

Development of l-lactate dehydrogenase biosensor based on porous silicon resonant microcavities as fluorescence enhancers

“…Specifically, pSi with a microcavity structure offers signal amplification for fluorescence or luminescence-based detection systems. This is because the microcavity, which is a multilayer consisting of alternating porosities and a spacer layer in between, is able to enhance the emission of a fluorophore confined in the porous structure according to the Purcell effect (DeLouise and Ouyang, 2009;Koenderink, 2010;Poitras et al, 2003;Purcell, 1946;Qiao et al, 2010;Setzu et al, 2000). This particular pSi architecture has therefore been applied to fluorescence biosensor applications (Krismastuti et al, 2014;Palestino et al, 2008Palestino et al, , 2009Sciacca et al, 2009).…”

Enhancement of QDs' fluorescence based on porous silicon Bragg mirror

“…Combining QDs with PSi and utilizing the photonic structure of PSi can fabricate biosensors with high sensitivity and excellent performance [18,19]. Hong Qiao et al [20] have embedded QDs inside PSi microcavity and enhanced fluorescence intensity of QDs successfully, what is more, they also reduced the FWHM of fluorescence spectra. They placed a multi-layer PSi free-standing film on a Bragg mirror, the free-standing film was lifted off the silicon substrate by electropolishing method.…”