New generation concentrated solar power (CSP) plants require new receiver materials with selective optical properties and excellent corrosion resistance against molten salts. MAX phases are promising for CSP applications due to their thermal shocks. Herein, we report a absorptance >/= 0.5 emittance of 0.17-0.31 between 600 1500 K Cr2AlC, Ti2AlC, Ti3AlC2. These compositions were also exposed sal...

For ultrathin films of a given material, light absorption is proportional to the film thickness. However, if the optical constants of the film are chosen in an optimal way, light absorption can be high even for extremely thin films and optical path length. We derive the optimal conditions and show how the maximized absorptance depends on film thickness. It is then shown that the optimal situati...

The main objective of this article is to present the calibration process of a computer model of a naturally-ventilated house built in southern Brazil. The house was monitored over two seven-day periods by using Hobo data loggers. The EnergyPlus computer program was used to create a computer model for the house; parameters related to air infiltration and natural ventilation were modeled by using...

Ultrafast pulsed laser irradiation is demonstrated to be able to produce surface nano-structuring and simultaneous crystallization of amorphous silicon thin film in one step laser processing. After fs laser irradiation on 80 nm-thick a-Si deposited on Corning 1737 glass substrate, the color change from light yellow to dark brown was observed on the sample surface. AFM images show that the surfa...

We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gol...

In this paper, we use the transfer matrix method to calculate the optical absorptance of vertically-aligned silicon nanowire (SiNW) arrays. For fixed filling ratio, significant optical absorption enhancement occurs when the lattice constant is increased from 100 nm to 600 nm. The enhancement arises from an increase in field concentration within the nanowire as well as excitation of guided reson...

Optical characterization methods were applied to a series of microcrystalline silicon thin films and solar cells deposited by the very high frequency glow discharge technique. Bulk and surface light scattering effects were analyzed. A detailed theory for evaluation of the optical absorption coefficient a from transmittance, reflectance and absorptance ~with the help of constant photocurrent met...