No electrical material properities

Thank you for contacting Lumerical support. Before proceeding, please note that this is a public forum and anything you post will be visible to the general public. For users residing in the United States, please ensure that the files and information contained within your posts are not International Traffic in Arms Regulations (ITAR) or export controlled.

To help us solve your issue as quickly as possible, please provide the following information:

1. What device are you trying to simulate? Include diagrams if available.

I want to simulate the band structure of a semiconductor superlattice.

2. What results are you trying to obtain? Be as specific as possible.
Band structure under an applied voltage.

3. Description of the problem or issue.
No electrical material properties are defined for domain 1, but I select the background material as Air.

4. Lumerical product and software version.
2020-R2

5. Please attach your simulation files, including any logs.1
the simulation file is too big to be uploaded (17M)

Hi,

As you suggested, this is usually related to the domain not having a material assigned to it. When changing the materials, the lock mesh option needs to be disabled for the simulation to be updated with the new settings. Please refer to this discussion for more information.

If could share your simulation I would be glad to take a look. Saving the file in analysis mode (without the results stored) can reduce the size. If this will not help you may need to use external links to share your file.

Kind regards

Thank you. Could you tell me where I can find the lock mesh option ? I simply did “partition”, “mesh” and “run” again and it didn’t work.
I shared it through Onedrive, please check. Many thanks.
https://1drv.ms/u/s!AvegQ6zHijOYhkS9aFY_AldkmGdi?e=Klrd7m

Here the error occurs because the material properties for Au and Ti are taken from the optical material database, while electrical properties are needed:

material_database

You would need to create the material from the indicated database and update the objects with the correct information.

Once this issue is resolved, another problem would be certain surfaces in the simulation being shared by more than one metal. This is not allowed as described in this article.

Could you tell me where I can find the lock mesh option ?

The lock mesh option is accessible by editing the charge solver object (mesh needs to be generated for the simulation):

lock_mesh

In your simulation, this is not causing an issue since it is not enabled. More information about this feature is presented in this article. Moreover, our CHARGE course can be a valuable resource for getting started with the solver.

Kind regards

Hi, the simulation has successfully run, but there seem to be some problems with the output.

Above image is the output bandstructure, but as I zoom in, some discontinuities appear, see below..

But could we get similar results shown below using Lumerical tools.3

. And could we get carries wave functions?

The latest simulation file is shared by OneDrive. https://1drv.ms/u/s!AvegQ6zHijOYhkeaYheDYci9Ol4U?e=ln3Voh Many thanks.