Single-layer design

To summarize, the principal advantages of multiple layer coatings over single layer designs are reduced thickness (reduced materials cost) and less stringent requirements on the material formulation. The principal disadvantage is the additional manufacturing steps required. 

FIGURE 7.12 Various insulated wire mounting designs for cone calorimeter tests single-layer design and bundle design (From Ref. 62, cop3rright 2005, John Wiley Sons, Ltd., with permission.)... 

Fig. 10. Typical design for single-layer photovoltaic device.

The design of cover systems is site-specific and depends on the intended function of the final cover—components can range from a single-layer system to a complex multilayer system. To minimize percolation, conventional cover systems use low-permeability barrier layers. These barrier layers are often constructed of compacted clay, geomembranes, geosynthetic clay liners, or combinations of these materials. 

All three are designed for low loss at A = 690 nm, i.e., the layer thicknesses fulfill (18.1). The solid line corresponds to the case where N = 1 for all layers. The dashed line corresponds to the case where only a single layer (the first bottom layer) was changed to N = 3. The loss minimum at 690 nm remains, but the behavior at other wavelengths changes substantially. Changing both the first and second layer to N = 3 results in the dotted line, which differs from both previous spectra. 

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