Question about Planar + Pyramid Silicon Solar Cells
I am trying to modify the TiO2 pyramids solar cell example but first want to make sure that without the pyramids, I would get the same thing as with the planar silicon solar cell example (given identical thicknesses of the active layer).
Starting with the FDTD simulations after deactivating the pyramids, I noticed that the source only started at 0.4 nm instead of 0.3 nm (like it did in the planar cell), which was the source of a good amount of the discrepancy in predicted J_SC. I also noticed that in the planar example, the bottom 0.1 um or so had a 100x generation rate than the region directly above it, which I wasn't sure whether that was an artifact of the simulation setup or an actual effect due to the proximity of the aluminum layer below it, so I shortened the solar generation region to exclude that.
Despite these changes, I still notice a big difference in predicted J_SC between the planar silicon solar cell example and the TiO2 pyramid version of a planar solar cell (w/ deactivated pyramids). I noticed that the generation rate in the planar cell seemed to decay over longer length scales through the cell than the generation rate in the pyramid version of the planar cell, as shown in the screenshots, but I have no idea why that would be since the materials used are the same. Can you please help with this? This seems too significant a difference to write off as just "simulation error", and having reliable starting points is essential for comparing different structures.