title: Nanoimprinted diffraction gratings for crystalline silicon solar cells: implementation, characterization and simulation.
abstract: Light trapping is becoming of increasing importance in crystalline silicon solar cells as thinner wafers are used to reduce costs. In this work, we report on light trapping by rear-side diffraction gratings produced by nano-imprint lithography using interference lithography as the mastering technology. Gratings fabricated on crystalline silicon wafers are shown to provide significant absorption enhancements. Through a combination of optical measurement and simulation, it is shown that the crossed grating provides better absorption enhancement than the linear grating, and that the parasitic reflector absorption is reduced by planarizing the rear reflector, leading to an increase in the useful absorption in the silicon. Finally, electro-optical simulations are performed of solar cells employing the fabricated grating structures to estimate efficiency enhancement potential.
authors.affiliation: Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr 2, 79110 Freiburg, Germany. alex.mellor@ies-def.upm.es
authors.forename: Alexander
authors.initials: A
authors.lastname: Mellor
authors.forename: Hubert
authors.initials: H
authors.lastname: Hauser
authors.forename: Christine
authors.initials: C
authors.lastname: Wellens
authors.forename: Jan
authors.initials: J
authors.lastname: Benick
authors.forename: Johannes
authors.initials: J
authors.lastname: Eisenlohr
authors.forename: Marius
authors.initials: M
authors.lastname: Peters
authors.forename: Aron
authors.initials: A
authors.lastname: Guttowski
authors.forename: Ignacio
authors.initials: I
authors.lastname: Tobías
authors.forename: Antonio
authors.initials: A
authors.lastname: Martí
authors.forename: Antonio
authors.initials: A
authors.lastname: Luque
authors.forename: Benedikt
authors.initials: B
authors.lastname: Bläsi