Getting Ray Tracing and TMM to agree in TCAD Sentaurus

[etoni044]

Hello,

I am working on simulating solar cells in TCAD Sentaurus. Right now I am working with flat-surface solar cells where using the Transfer Matrix Method (TMM) for optical carrier generation is appropriate. However, I would like to add surface texturing, which will require using Ray Tracing instead of TMM. The solar cells I am simulating have optically-thin layers of highly doped silicon, which cause issues when doing Ray Tracing, but not with TMM.

How can I get my Ray Tracing and TMM results to match in Sentaurus for flat solar cells using optically thin layers of materials? When I test flat solar cell structures with optically thick materials, Ray Tracing and TMM output the same results. Now, I need to get them to agree for optically thin layers. I have tried using thin film boundary conditions in SDevice for my antireflection coatings and highly-doped layers of silicon as follows:


Physics (RegionInterface="frontArc/topair"){
RayTraceBC ( TMM (
ReferenceMaterial = "Gas"
LayerStructure {
@dFrontARC@ "Nitride";
@dEmitter@ "Silicon"; } ) )
}
Physics (RegionInterface="rearArc/botair"){
RayTraceBC ( TMM (
ReferenceMaterial = "Gas"
LayerStructure {
@dRearARC@ "SiO2";
@dBase@ "Silicon"; } ) )
}

However, my results are still not agreeing with the same cell using TMM. Does anyone have any idea of how best to get Ray Tracing to handle optically thin layers?

Thank you,
Erin