title: Demonstration of Resonance Coupling in Scalable Dielectric Microresonator Coatings for Photovoltaics.
abstract: To increase the power conversion efficiency of solar cells, improved antireflection coatings are needed to couple light into the cell with minimal parasitic loss. Here, we present measurements and simulations of an antireflection coating based on silicon dioxide (SiO2) nanospheres that improve solar cell absorption by coupling light from free space into the absorbing layer through excitation of modes within the nanospheres. The deposited monolayer of nanospheres leads to a significant increase in light absorption within an underlying semiconductor on the order of 15-20%. When the periodicity and spacing between the nanospheres are varied, whispering gallery-like modes can be excited and tuned throughout the visible spectrum. The coating was applied to a Si solar cell containing a Si3N4 antireflection layer, and an additional increase in the spectral current density of ∼5% was found. The fabrication process, involving Meyer rod rolling, is scalable and inexpensive and could enable large-scale manufacturability of microresonator-based photovoltaics.
authors.affiliation: Department of Electrical and Computer Engineering, University of Maryland , College Park, Maryland 20742, United States.|Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Dongheon
authors.initials: D
authors.lastname: Ha
authors.affiliation: Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, Maryland 20742, United States.|Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Chen
authors.initials: C
authors.lastname: Gong
authors.affiliation: Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, Maryland 20742, United States.|Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Marina S
authors.initials: MS
authors.lastname: Leite
authors.affiliation: Department of Electrical and Computer Engineering, University of Maryland , College Park, Maryland 20742, United States.|Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Munday
keywords: absorptivity enhancement; antireflection coatings; microresonator; photocurrent enhancement; whispering gallery modes