Presentation
17 September 2018 Porous silicon devices and applications (Conference Presentation)
Author Affiliations +
Abstract
Three-dimensional nanoporous silicon (PSi), with inherently large surface areas, tunable pore sizes, film thicknesses, and effective refractive indices, has been utilized as a platform for the detection of biomolecules and high-dose radiation. A brief overview of the fabrication and characterization of the nanoporous framework is presented for novel applications that benefit from such sponge-like, high surface area devices. For many of these applications, it is necessary to ensure that the PSi surfaces are well-passivated and stabilized for subsequent conjugation with linker molecules and for emitters to maintain their emissive properties post-integration with the porous matrix. We present a detailed analysis of the influence that varied levels of interfacial oxide (SiOx) growth has on the optical properties of quantum dots (QDs) immobilized within the PSi thin-films. Reflectance spectroscopy, continuous wave photoluminescence (CWPL) and time-resolved photoluminescence (TRPL) studies provide a comprehensive understanding of the complex QD exciton dynamics at the PSi/SiOx-QD interfaces. The gradual conversion of PSi thin-films into fully-oxidized porous silicon oxide (PSiO2) thin-films is shown to significantly suppress non-radiative recombination pathways of photogenerated QD excitons and achieve almost a five-fold increase in QD exciton lifetimes. This conversion of PSi into PSiO2, a wide bandgap nanoporous material, also circumvents loss of QD emission due to absorption by PSi based devices. Future avenues of research into PSi based devices will be presented based on analyzing the optical scattering response of nanoscale PSi annular rings fabricated over PSi Bragg mirrors via dark field microscopy.
Conference Presentation
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Girija Gaur, Dimitry Koktysh, Sharon Weiss, and Shuren Hu "Porous silicon devices and applications (Conference Presentation)", Proc. SPIE 10754, Wide Bandgap Power and Energy Devices and Applications III, 1075409 (17 September 2018); https://doi.org/10.1117/12.2323201
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KEYWORDS
Silicon

Silicon films

Analytical research

Integrated optics

Microscopy

Optical biosensors

Optical sensors

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