Efficient light-trapping with quasi-periodic uniaxial nanowrinkles for thin-film silicon solar cells. (May 2017)

• Record Type: Journal Article
• Authors: Ram, Sanjay K.; Desta, Derese; Rizzoli, Rita; Falcão, Bruno P.; Eriksen, Emil H.; Bellettato, Michele; Jeppesen, Bjarke R.; Jensen, Pia B.; Summonte, Caterina; Pereira, Rui N.; Larsen, Arne Nylandsted; Balling, Peter
• Is Part Of: Nano energy. Volume 35(2017:May)
• Page Start: 341
• Page End: 349
• Publication Date: 2017-05
• Subjects: Silicon thin-film solar cells -- Photovoltaic devices -- Nanowrinkles -- Light-management -- Nanomolding -- Finite element method modeling; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2017.04.016
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Self-organizing nanopatterns can enable economically competitive, industrially applicable light-harvesting platforms for thin-film solar cells. In this work, we present transparent solar cell substrates having quasi-periodic uniaxial nanowrinkle patterns with high optical haze values. The self-organized nanowrinkle template is created by controlled heat-shrinking of metal-deposited pre-stretched polystyrene sheets. A scalable UV-nanoimprinting method is used to transfer the nanopatterns to glass substrates on which single-junction hydrogenated amorphous silicon p-i-n solar cells are subsequently fabricated. The structural and optical analyses of the solar cell show that the nanowrinkle pattern is replicated throughout the solar cell structure leading to enhanced absorption of light. The efficient broadband light-trapping in the nanowrinkle solar cells results in very high 18.2 mA/cm 2 short-circuit current density and 9.5% energy-conversion efficiency, which respectively are 35.8% and 39.7% higher than the values obtained in flat-substrate solar cells. The cost- and time-efficient technique introduces a promising new approach to customizable light-management strategies in thin-film solar cells. Graphical abstract: Highlights: Quasi-periodic nanowrinkle (NW) substrates with high optical haze (∼60%) fabricated. NW design leads to broadband light trapping in p-i-n a-Si:H solar cells. NW cells achieve 9.5% energy conversion efficiency and 18.2 mA/cm 2 current density. Simulation results identify inter-wrinkle areas as high absorption hotspots.