Geometry building issue in simulation with planar solids

can you help to solve this error

Hi. It looks like an issue with geometry building. Can you share the file with me?

​This is the structure file .Thanks for help

Dear all,
Can you check my structure ,please.

Hi @fKorany, Thanks for sharing the file. I was able to mesh part of the structure (just the active region without the top metal) but not all of it. I will try to spend some more time on it and get back to you within a couple of days. Thanks for waiting.

Thank for your help.

Hi @fKorany, I have checked your file with the help of a colleague and the problem is definitely arising from the fact that you have two planar solids touching each other. When the solver tries to combine the two objects, mapping the faces on one planar solid to the faces of the other one is creating the issue (most likely). As obvious solution would be to combine the two structures and create a single planar solid structure. You can find some information about how to create structures using planar solids here: Some more helpful instructions in creating an arbitrary geometry using planar solid.

A second solution which is more of a workaround the problem is to move the top planar solid slightly into the bottom one. In the attached file I have lowered the top planar solid just by 1 nm so that it now overlaps with the bottom one (instead of touching it). The solver is now able to mesh the structure without any error.

geometry_issue_solution.ldev (6.0 MB)

The final structure is slightly different from your original one but hopefully it is not so different to affect the result significantly.

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Hi aalam,
Thanks for your help. What about radial doping for this file? .Can create radial doping instead of axial doping to improve results.
Thanks in advance.

Hi aalam ,

Another error message appeared.

Hi @fKorany, It looks like that you have a new planar solid in the Objects tree. That could be creating the issue again. Have you tried using a slight overlap again like last time?

Hi @fKorany, radial doping will be needed if you are using shell doping on this device. Otherwise there is no need for radial doping. If you would like to use radial doping then please take a look at these posts on how to create them:

How to add a constant radial doping profile in DEVICE

Creating radial doping profile for a truncated cone

Hi aalam,
Thanks for help. Can you explain how i can do shell doping for this file in
Thanks in advance.

Hi aalam,
Another question for axial doping if the generation rate file includes
silicon nanowire and silicon substrate area , what about the ideal depth
for n doping junction depth and p doping depth. Where for each n doping i
found different value for efficiency.
Thanks in advance.

Please take a look at this post:

Hi @fKorany, I believe you should be much more qualified to answer this question than me as I am not an expert in solar cell design. However, my two cents would be to run multiple simulations with different doping depths and record the efficiency. The doping profile that gives you the best efficiency should ideally be the one to use in the end.

Hi aalam,
Thanks for your great help. Can you show for me if i simulate silicon
nanowire over silicon substrate and i determine apart of nanowire as n
doping , i should determine the other part and substrate as p doping or i
can separate between n doping and p doping.
Thanks in advance.

Hi @fKorany, The doping objects are additive. So to keep things simple I would recommend using different objects for n and p type doping. You can use one import doping to dope the surface of the nanowire with n-doping (say) and then use another (say) constant doping object to dope the core of the nanowire and the substrate with p doping. Finally I am guessing that you would use a third constant doping object to heavily dope the interface between the substrate and the bottom contact to create ohmic contacts. The post I mentioned above shows how to use the additive nature of the doping objects to create a ring type p-n doping: