Abstract
Despite their seemingly random appearances in the real space, quasi-andom nanophotonic structures exhibit distinct structural correlations and have been widely utilized for effective photon management. However, current design approaches mainly rely on the deterministic representations consisting two-dimensional (2D) discretized patterns in the real space. They fail to capture the inherent non-deterministic characteristic of the quasi-random structures and inevitably result in a large design dimensionality. Here, we report a new design approach that employs the one-dimensional (1D) spectral density function (SDF) as the unique representation of non-deterministic quasi-random structures in the Fourier space with greatly reduced design dimensionality. One 1D SDF representation can be used to generate infinite sets of real space structures in 2D with equally optimized performance, which was further validated experimentally using light-trapping structures in a thin film absorber as a model system. The optimized non-deterministic quasi-random nanostructures improve the broadband absorption by 225% over the unpatterned cell.
Original language | English (US) |
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Article number | 3752 |
Journal | Scientific reports |
Volume | 7 |
Issue number | 1 |
DOIs | |
State | Published - Dec 1 2017 |
Funding
This work is supported by National Science Foundation under grants CMMI-1130640 and EEC-1530734. We thank Dr. David Czaplewski at Argonne National Lab in assisting with a-Si deposition. The use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-6CH11357. This work also made use of the EPIC facility and Keck-II facility (NUANCE Center-Northwestern University), which has received support from the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the Nanoscale Science and Engineering Center (NSF EEC-0647560) at the International Institute for Nanotechnology; and the State of Illinois, through the International Institute for Nanotechnology. S.Y. also thanks the International Institute for Nanotechnology for the Ryan Fellowship award.
ASJC Scopus subject areas
- General