title: Electrochemically synthesized broadband antireflective and hydrophobic GaOOH nanopillars for III-V InGaP/GaAs/Ge triple-junction solar cell applications.
abstract: We report the efficiency enhancement of III-V InGaP/GaAs/ Ge triple-junction (TJ) solar cells using a novel structure, i.e., vertically-oriented gallium oxide hydroxide (GaOOH) nanopillars (NPs), as an antireflection coating. The optical reflectance properties of rhombus-shaped GaOOH NPs, which were synthesized by a simple, low-cost, and large-scalable electrochemical deposition method, were investigated, together with a theoretical analysis using the rigorous coupled-wave analysis method. For the GaOOH NPs, the solar weighted reflectance of ~8.5% was obtained over a wide wavelength range of 300-1800 nm and their surfaces exhibited a high water contact angle of ~130° (i.e., hydrophobicity). To simply demonstrate the feasibility of device applications, the GaOOH NPs were incorporated into a test-grown InGaP/GaAs/Ge TJ solar cell structure. For the InGaP/GaAs/Ge TJ solar cell with broadband antireflective GaOOH NPs, the conversion efficiency (η) of ~16.47% was obtained, indicating an increased efficiency by 3.47% compared to the bare solar cell (i.e., η~13%).
authors.forename: Jung Woo
authors.initials: JW
authors.lastname: Leem
authors.forename: Hee Kwan
authors.initials: HK
authors.lastname: Lee
authors.forename: Dong-Hwan
authors.initials: DH
authors.lastname: Jun
authors.forename: Jonggon
authors.initials: J
authors.lastname: Heo
authors.forename: Won-Kyu
authors.initials: WK
authors.lastname: Park
authors.forename: Jin-Hong
authors.initials: JH
authors.lastname: Park
authors.forename: Jae Su
authors.initials: JS
authors.lastname: Yu