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    Category Chemistry/Nanotechnology

    Insect Eyes Inspire new Solar cell design

    September 2, 2017, Categories  Technology/Electronics, Chemistry/Nanotechnology, Physics

    Scaffolds in a compound solar cell filled with perovskite after fracture testing. Credit: Dauskardt Lab/Stanford University

    Scaffolds in a compound solar cell filled with perovskite after fracture testing. Credit: Dauskardt Lab/Stanford University

    Packing tiny solar cells together, like micro-lenses in the compound eye of an insect, could pave the way to a new generation of advanced photovoltaics. In a new study, the Stanford team used the insect-inspired design to protect a fragile photovoltaic material, perovskite from deteriorating when exposed to heat, moisture or mechanical stress. The results are published in the journal Energy & Environmental Science (E&ES).

    “Perovskites are promising, low-cost materials that convert sunlight to electricity as efficiently as conventional solar cells made of silicon,” said Reinhold Dauskardt, a professor of materials science and engineering and senior author of the study...

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    Researchers validate UV light’s use in improving Semiconductors

    August 30, 2017, Categories  Physics, Technology/Electronics, Chemistry/Nanotechnology

    Schematic of the epitaxial growth procedure of ZnSe/GaAs heterostructure growth using either light-start or dark-start growth procedures. (a) Prior to ZnSe epilayer growth, the GaAs epilayer was grown in a dedicated III-V MBE chamber and was covered with an amorphous arsenic film prior to transferring it to a dedicated II-VI chamber. (b) The amorphous arsenic film was then thermally desorbed and the interface growth was initiated with a Zn pre-treatment under either a light-start or dark-start condition. During light-start sample growth, UV light was directed onto the growth surface from the beginning of Zn pre-treatment until the end of the ZnSe growth (f–h). During dark-start sample growth, UV light was directed onto the growth surface only during ZnSe epilayer growth (c–e).

    Schematic of the epitaxial growth procedure of ZnSe/GaAs heterostructure growth using either light-start or dark-start growth procedures. (a) Prior to ZnSe epilayer growth, the GaAs epilayer was grown in a dedicated III-V MBE chamber and was covered with an amorphous arsenic film prior to transferring it to a dedicated II-VI chamber. (b) The amorphous arsenic film was then thermally desorbed and the interface growth was initiated with a Zn pre-treatment under either a light-start or dark-start condition. During light-start sample growth, UV light was directed onto the growth surface from the beginning of Zn pre-treatment until the end of the ZnSe growth (f–h). During dark-start sample growth, UV light was directed onto the growth surface only during ZnSe epilayer growth (c–e).

    A discov...

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    A Low-Cost method for Solar-Thermal Conversion that’s Simpler and Greener

    August 29, 2017, Categories  Physics, Technology/Electronics, Chemistry/Nanotechnology

    1. The selective solar absorber (SSA) developed by the researchers appears black, and thus absorptive, under sunlight (as shown on the photograph on the left). However, for thermal radiation, it behaves like a non-emissive metal mirror (reflecting the dark blue sky, as shown on the thermograph on the right), and prevents the absorbed solar energy from being radiated away and lost. —Figure courtesy of Jyotirmoy Mandal and Yuan Yang/Columbia Engineering 2. The researchers make their SSAs using a dip-and-dry technique which is considerably simpler than common manufacturing methods for SSAs. —Photo courtesy of Jyotirmoy Mandal and Yuan Yang/Columbia Engineering

    1. The selective solar absorber (SSA) developed by the researchers appears black, and thus absorptive, under sunlight (as shown on the photograph on the left). However, for thermal radiation, it behaves like a non-emissive metal mirror (reflecting the dark blue sky, as shown on the thermograph on the right), and prevents the absorbed solar energy from being radiated away and lost.
    —Figure courtesy of Jyotirmoy Mandal and Yuan Yang/Columbia Engineering
    2. The researchers make their SSAs using a dip-and-dry technique which is considerably simpler than common manufacturing methods for SSAs.
    —Photo courtesy of Jyotirmoy Mandal and Yuan Yang/Columbia Engineering

    Dip-and-dry’ approach for selective solar absorbers exhibit high-performance and durability...

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    Solar Hydrogen production by Artificial Leafs: a special treatment Improves cheap Metal Oxide Photoelectrodes

    August 29, 2017, Categories  Technology/Electronics, Chemistry/Nanotechnology

    Metal oxides are promising candidates for cheap and stable photoelectrodes for solar water splitting, producing hydrogen with sunlight. Unfortunately, metal oxides are not highly efficient in this job. A known remedy is a treatment with heat and hydrogen. An international collaboration has now discovered why this treatment works so well, paving the way to more efficient and cheap devices for solar hydrogen production. Credit: HZB

    Metal oxides are promising candidates for cheap and stable photoelectrodes for solar water splitting, producing hydrogen with sunlight. Unfortunately, metal oxides are not highly efficient in this job. A known remedy is a treatment with heat and hydrogen. An international collaboration has now discovered why this treatment works so well, paving the way to more efficient and cheap devices for solar hydrogen production. Credit: HZB

    The fossil fuel age is bound to end, for several strong reasons. The gas has a huge energy density, it can be stored or processed further, e. g. to methane, or directly provide clean electricity via a fuel cell. If it is produced using sunlight alone, hydrogen is completely renewable with zero carbon emissions...

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