Back reflector coating using a photonic crystal for highly efficient solar cells using a new metamaterial with the most extreme positive index of refraction

• Published in: Indian journal of physics Vol. 97; no. 2; pp. 577 - 588
• Main Authors: Taya, Sofyan A., AbuIbaid, Sahar M., Alhamss, Dana N., Patel, Shobhit K., Colak, Ilhami, Almawgani, Abdulkarem H. M.
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01.02.2023; Springer Nature B.V
• Subjects: Astrophysics and Astroparticles; Bandstop filters; Extreme values; Metamaterials; Original Paper; Photonic crystals; Photovoltaic cells; Physics; Physics and Astronomy; Refraction; Refractivity; Silicon dioxide; Solar cells; Thickness; Thin films; Binary photonic crystal; Silicon solar cells; Metamaterial; Omnidirectional reflection; Back reflector
• ISSN: 0973-1458; 0974-9845
• DOI: 10.1007/s12648-022-02403-2

A Korean team fabricated a novel metamaterial with an index of refraction of 38.6 which is considered the most extreme positive value. In this paper, we employ the new metamaterial to construct a binary photonic crystal having the structure air/(metamaterial/SiO 2 ) N /Si. The binary photonic crystal is employed as a back reflector of a thin-film silicon solar cell. The proposed back reflector has a very thin thickness of about 312 nm. It is found that the omnidirectional region for which we have 0% transmittivity for all incident angles and for simultaneously TE and TM modes is 341.8 nm in the visible region whereas it is only 155.1 nm for a structure consisting of (Si/SiO 2 ) N . We believe that we have a perfect back reflector with three significant properties: 1- it has a very wide bandwidth, 2- the bandwidth is in the visible range of the solar spectrum, and 3- it has a thin thickness. In addition to a back reflector, the proposed structure can be used as a wide band-stop filter.