Prof. Parvaneh Mokarian-Tabari Profile

Prof. Parvaneh Mokarian-Tabari

Research Associate Professor at Trinity College Dublin

SPIE Involvement:

Author

Area of Expertise:

Polymer physics , Properties of polymer thin films at interfaces and surfaces , Block copolymer nanolithography for microelectronics and optics , Functional surfaces , Structural antireflective surfaces

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Company Website

Proceedings Article | 20 August 2020 Poster

Block co-polymers for etch mask definition to create anti-reflective surfaces

Brian Jennings, Riley Gatensby, Elsa Giraud, Andrew Selkirk, Sajjad Mir, Ramsankar Senthamaraikannan, Parvaneh Mokarian-Tabari

Proceedings Volume 11467, 1146727 (2020) https://doi.org/10.1117/12.2568487

KEYWORDS: Etching, Glasses, Metals, Nickel, Oxides, Optical components, Optical lithography, Reflectivity, Refractive index, Visible radiation

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Proceedings Article | 26 July 2016 Presentation

Nanopatterning by large block copolymers for application in photonic devices (Conference Presentation)

Parvaneh Mokarian-Tabari, Ramsankar Senthamaraikannan, Timothy Collins, Colm Glynn, Colm O'Dwyer, Michael Morris

Proceedings Volume 9885, 98850B (2016) https://doi.org/10.1117/12.2227766

KEYWORDS: Silicon, Nanolithography, Nanostructures, Photonic devices, Reflectivity, Photonic crystals, Manufacturing, Polymers, Infrared cameras, Molecular self-assembly

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The extensive benefits of the new generation of nanostructured surfaces is very promising for enhancing light absorption efficiency in photonic devices. However, the low throughput and the high cost of available technologies such as lithography for fabrication of nanostructures has proved to be a difficult technological hurdle for advanced manufacturing. In this research we present a solution based process based on high molecular weight block copolymer (BCP) nanolithography for fabrication of periodic structures on large areas of optical surfaces. Block copolymer self- assembly technique is a solution based process that offers an alternative route to produce highly ordered photonic crystal structures. BCPs forms nanodomains (5-10 nm) due to microphase separation of incompatible constitute blocks. The size and shape of the nanostructure can be customised by the molecular weight and volume fraction of the polymer blocks. However, the major challenge is BCPs do not phase separate into their signature ordered pattern above 100 nm, whereas for nanofeatures to be used as photonic gratings, they must be greater than 100 nm (typically ¼ wavelength). This is due to significant kinetic penalty arising from higher entanglement in high molecular weight polymers. In this work we present the results of exploiting commercially available block copolymers to phase separate into periodic domains greater than 100 nm. The process do not include any blending with homopolymers, or adding colloidal particles, and to our best knowledge, has not been yet achieved or reported in the literatures. We have pattern transferred the BCP mask to silicon substrate by reactive ion etch (ICP-RIE). The final product is black silicon, consists of hexagonally packed conic Si nanofeatures with diameter above 100nm and periodicity of 200 nm. The height of the Si nanopillars varies from 100 nm to 1 micron. We have characterized the angle dependent optical reflectance properties of the black silicon. The antireflective properties of the Si nanofeatures were probed in the 400 nm – 2500 nm wavelength range and compared to an Au reflectance standard. As the subwavelength grating is made from the same material as the substrate (Si), the index matching at the substrate interfaces has lead to highly improved antireflecting performance. The reflectivity of the silicon substrate shows one order of magnitude reduction in a broad range of wavelength from NIR to UV-visible, below 1%. The simplicity of the solution based large block copolymer nanolithography and the capability of integration to existing fabrication process, makes this novel technique a very attractive alternative for manufacturing photonic crystals on large, arbitrary shaped and curved objects such as photovoltaics and IR camera lenses for medical imaging.

Conference Committee Involvement (2)

Micro- and Nanotechnology Sensors, Systems, and Applications VII

20 April 2015 | Baltimore, MD, United States

Micro- and Nanotechnology Sensors, Systems, and Applications VI

5 May 2014 | Baltimore, MD, United States

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