Open AccessLight trapping efficiency of organic solar cells with large period photonic crystals
Author(s) -
Laurent Peres,
Valérie Vigneras,
Sophie Fasquel
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.0a1229
Subject(s) - photonic crystal , materials science , optoelectronics , optics , wavelength , trapping , absorption (acoustics) , visible spectrum , photonics , period (music) , active layer , electrode , refractive index , layer (electronics) , physics , nanotechnology , ecology , quantum mechanics , acoustics , biology , thin film transistor
We study the optical properties of a 2D Photonic Crystal (PC) inserted in the upper ITO electrode of a classical P3HT:PCBM solar architecture with an ultra-thin active layer. First, we analyze the optical response of the system when only the active layer is supposed to absorb light. This allows us to observe clear photonic crystal resonances in the absorption spectrum, which increase the cell efficiency even if the period of the PC is higher than the wavelength. This is in apparent contradiction with the common belief that PC should work in subwavelength regime. Then, by turning to a real system (with optical losses in all the layers), an optimized PC design is proposed, where the maximum of efficiency is obtained for a PC period of 1200 nm, much larger than visible wavelength.