Bandstructure of W shape Silicon

Silicon W_bandstructure.fsp (737.1 KB) Silicon W_bandstructure.lsf (1.3 KB)

Hello, I met a problem when I want to simulate the bandstructure of W shape Silicon substrate. the dispersion curve is a straight line parallel to k axis always. Could you help me check it?

Hello @tingting.zhai,

Thank you for the question. It looks like you’re basing your simulation on the Square 2D bandstructure example. This is a good approach, but you also need to make sure that your model setup script works with your new simulation. We can see here that the script encounters an error because there is no object named rect_pc in your simulation, so the rest of the script doesn’t run.

You need to make sure that your simulation objects are designed such that the setup scripts in your structure and analysis groups run properly. In particular, you will have to make some modifications due to the fact that the original example is periodic in the y direction and your simulation is not. You will probably have to go through each of the analysis groups and make sure they are set up for a simulation that is only periodic in the x direction.

For example, notice in the above image that the model setup script sets the y span of the FDTD region to be ay, the periodicity in the y direction. This doesn’t make sense for your simulation, so you should remove this line.

I hope this helps. Let me know if you have any questions.

1 Like

Hello Kjohnson,

Thank you very much for your detailed explanation. I changed the script as you told me. I attached the files, and the result behaves like below. Do you think it’s correct ? Could you give me some explanations from the result I get?

I also attached a file to simulate the bandstructure of graphene, but the result seems not correct.

Also I read the example Simple Glass-Silver-Air Slab , the following two files, the y span is 1 nm. However , if I use a larger y span, the dispersion curve totally changed. Could you tell me the reason.


Looking forward to your reply!

Best regards,


graphene sheet_bandstructure1.fsp (737 KB)

Silicon W_bandstructure.lsf (1.27 KB)

Silicon W_bandstructure.fsp (1.48 MB)

Silicon W_bandstructure.lsf (1.27 KB)