On the efficient optimization of optical properties of particulate monolayers by a hybrid finite element approach

This article addresses the numerical simulation and optimization of the optical properties of mono-layered nano-particulate films. The particular optical property of interest is the so-called haze factor, for which a model close to an experimental setup is derived. The numerical solution becomes very involved due to the resulting size of computational domain in comparison to the wave length, rendering the direct simulation method infeasible. As a remedy, a hybrid method is suggested, which in essence consistently combines analytical solutions for the far field with finite element-based solutions for the near field. Using a series of algebraic reformulations, a model with an off- and online component is developed, which results in the computational complexity being reduced by several orders of magnitude. Based on the suggested hybrid numerical scheme, which is not limited to the haze factor as objective function, structural optimization problems covering geometrical and topological parametrizations are formulated. These allow the influence of different particle arrangements to be studied. The article is complemented by several numerical experiments underlining the strength of the method.

Textured transparent conductive B/Al doped ZnO films utilizing reactive magnetron sputtering

Total transmittance (Ttot, solid line) and haze factor (HT, dashed line) of the etched ZnO:B-320, ZnO:B/Al-450 and ZnO:Al films.

An Average Slope Factor for Solar Insolation

Design methods for solar collector sizing (such as f-chart) usually require a multiplying factor (the slope factor) to correct insolation data taken on the horizontal for the tilt angle of the solar collector. The slope factor is a function of the haze factor (KT) at each location which varies month to month. A simplification (with attendant error) can be made for space heating by taking the 6 month average winter haze factor as a constant to get a single set of slope factor curves. For hot water heating a 12 month average of the haze factor is used to find the correct slope factor chart. Available slope factor equations using average haze factors were plotted to result in a chart whose parameters are latitude and month of year. Correction charts for off-average locations are presented. The error in the given slope factor charts is estimated to be accurate ± 7 percent for most cities.