Optimizing Absorptance in Selected Layers 

OptiLayer allows you to optimize absorptance of energy in one layer or in a group of layers. These layers are selected on the basis of material abbreviation, therefore these new targets also works with Needle synthesis.

In the solar cell presented on the right panel, we have a 5-layer coating. We assume  that all the incoming photons are converted into electric charges in the third layer (intrinsic a-Si:H) only. Our goal is to maximize the amount of light absorbed in the third layer by varying the thickness of all five layers.

The coating structure should be kept unchanged in the course of the optimization process, i.e. layer thicknesses must take values from the specified ranges. No layers can disappear. In this case constrained optimization method can be used. 

See our video example at YouTube YouTube.

Example: A solar cell structure (M. Zeman, “Optical modeling of a a-Si:H solar cells with rough interfaces: Effect of back contract and interface roughness”, J. of Appl. Phys., Vol. 88, 2000)

coatings for solar cells

Design structure: 

optical coatings for solar cells

Corresponding materials abbreviations: 

multilayer coatings for solar cells

In Layer Absorptance Target you should specify target absorption in a desired spectral range and push Target button.  

optimization layer absorptance

In the Layer Absorptance Target Selection dialog, you specify material abbreviation that will be used in the course of the optimization. In this example, layer number 3 is the layer of i-a-Si layer material. This material has the abbreviation IASI. We would like to maximize absorptance in this layer in the spectral range from 400 nm to 800 nm.

optimization layer absorptance 

Constrained optimization settings: 

 coatings for solar cells

As a result of the constrained optimization, the absorptance in the third layer is increased

optimization layer absorptance