title: Synergistically Enhanced Performance of Ultrathin Nanostructured Silicon Solar Cells Embedded in Plasmonically Assisted, Multispectral Luminescent Waveguides.
abstract: Ultrathin silicon solar cells fabricated by anisotropic wet chemical etching of single-crystalline wafer materials represent an attractive materials platform that could provide many advantages for realizing high-performance, low-cost photovoltaics. However, their intrinsically limited photovoltaic performance arising from insufficient absorption of low-energy photons demands careful design of light management to maximize the efficiency and preserve the cost-effectiveness of solar cells. Herein we present an integrated flexible solar module of ultrathin, nanostructured silicon solar cells capable of simultaneously exploiting spectral upconversion and downshifting in conjunction with multispectral luminescent waveguides and a nanostructured plasmonic reflector to compensate for their weak optical absorption and enhance their performance. The 8 μm-thick silicon solar cells incorporating a hexagonally periodic nanostructured surface relief are surface-embedded in layered multispectral luminescent media containing organic dyes and NaYF4:Yb3+,Er3+nanocrystals as downshifting and upconverting luminophores, respectively, via printing-enabled deterministic materials assembly. The ultrathin nanostructured silicon microcells in the composite luminescent waveguide exhibit strongly augmented photocurrent (∼40.1 mA/cm2) and energy conversion efficiency (∼12.8%) than devices with only a single type of luminescent species, owing to the synergistic contributions from optical downshifting, plasmonically enhanced upconversion, and waveguided photon flux for optical concentration, where the short-circuit current density increased by ∼13.6 mA/cm2compared with microcells in a nonluminescent medium on a plain silver reflector under a confined illumination.
authors.affiliation: School of Materials Science and Engineering, Kookmin University , Seoul 02707, Republic of Korea.
authors.forename: Sung-Min
authors.identifier: 0000-0001-9446-9122
authors.initials: SM
authors.lastname: Lee
authors.forename: Purnim
authors.initials: P
authors.lastname: Dhar
authors.forename: Huandong
authors.initials: H
authors.lastname: Chen
authors.forename: Angelo
authors.initials: A
authors.lastname: Montenegro
authors.forename: Lauren
authors.initials: L
authors.lastname: Liaw
authors.forename: Dongseok
authors.initials: D
authors.lastname: Kang
authors.forename: Boju
authors.initials: B
authors.lastname: Gai
authors.forename: Alexander V
authors.identifier: 0000-0001-7031-2630
authors.initials: AV
authors.lastname: Benderskii
authors.forename: Jongseung
authors.identifier: 0000-0001-5342-1181
authors.initials: J
authors.lastname: Yoon
keywords: luminescent solar concentrator; photovoltaics; plasmonic nanostructure; silicon solar cells; upconversion