Ashish Prajabati - Video Lecture

Ashish Prajabati - Video Lecture

IVS-IPSTA 2020 Online Conference December 13, 2020

Nanomaterials, Thin films, and Surface Science
Afternoon Session

Session chair:
Maya Bar-Sadan

Ben Gurion University of the Negev


Omnidirectional Absorption with Submicrometer-Scaled Compound Parabolic Light Concentrator Arrays

Ashish Prajabati

School of Electrical and Computer Engineering,
Ben Gurion University of the Negev, Israel


Abstract


Efficient omnidirectional broadband absorption is important to various applications involving the harvest of the solar spectrum. The optical absorption dependency on oblique illumination in arrays of submicrometer-scaled compound parabolic concentrators (CPCs) is examined. For a non-optimized CPC array, the broadband absorption is _30% higher than that of a nanopillar (NP) array that is corrected for the absorption of the solar light for an angle-of-illumination range of 0_–80_. It is shown that enhanced absorptivity of CPC arrays, relative to the optically corrected NP array, is due to the repressed transmission for both transverse electric and transverse magnetic illumination. It is determined that the superior omnidirectional broadband absorption of a CPC array is due to strong “light bending”; in the CPC array, the optical intensity is predominantly distributed laterally, whereas in the NP array, the optical intensity is mainly directed in the vertical direction. It is shown that for the CPC array, the intensity lateral components are up to 80% higher than the lateral components in the NP array. Finally, the CPC array omnidirectional broadband absorption is governed by substantial light bending, which induces competent excitation of various asymmetric photonic states.