Optimized design of moth eye antireflection structure for organic photovoltaics

• Published in: Journal of Coatings Technology and Research Vol. 13; no. 1; pp. 201 - 210
• Main Authors: Kubota, Shigeru, Kanomata, Kensaku, Ahmmad, Bashir, Mizuno, Jun, Hirose, Fumihiko
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.01.2016; American Coatings Association, Inc
• Subjects: Algorithms; Analysis; Chemistry and Materials Science; Corrosion and Coatings; Industrial Chemistry/Chemical Engineering; Materials Science; Mechanical properties; Moths; Optimization theory; Polymer Sciences; Surfaces and Interfaces; Thin Films; Tribology; United States; Organic solar cell; Moth eye; Optimization; FDTD
• ISSN: 1547-0091; 1945-9645; 1935-3804
• DOI: 10.1007/s11998-015-9745-5

To improve the power conversion efficacy of organic photovoltaics (OPVs), it is required to design antireflection structures that could realize efficient and broadband light trapping. In this article, we perform global optimization of the textured pattern of moth eye antireflection surfaces to maximize the short-circuit current density ( J SC ) of OPVs with a poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM)-based bulk heterojunction. We introduce an optimization algorithm consisting of two steps: in the first step, the simple grid search is conducted to roughly estimate a globally optimal solution, while in the second step, the Hooke and Jeeves pattern search is executed to refine the solution. By combining the optimization algorithm with the optical simulation based on the finite-difference time-domain method, we find the optimal period and height of moth eye array with which the level of J SC can be increased by 9.05% in the P3HT:PCBM-based organic solar cell. We also demonstrate that the optimized moth eye structure can significantly modify the light path at a long wavelength range to strengthen the electric field intensity and enhance energy absorption within the active layer.