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Where to find COMSOL 5.4 variable description with details?

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Hi Everyone,

I am trying to modify some predefined equations in COMSOL 5.4 using the equation view, but there are a lot more variables than I expected. I don't know what many do and the short description in equation view does not help much.

For example, in the Semiconductor module, the Metal Contact has a variable called semi.bcAn with the description "SG exponential term for electrons at the boundaries ". I have no idea what that means. One could try and figure out by analyzing the way the variables are connected to one another. But with hundreds of them in the whole model, it's very time consuming.

Is there some document where can I find some more details on the variables? The COMSOL documentation doesn't seem to include anything beyond basic stuff. Thank you!


2 Replies Last Post Jun 14, 2019, 7:21 a.m. EDT
Chien Liu COMSOL Employee

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Posted: 5 years ago Jun 13, 2019, 1:22 p.m. EDT
Updated: 5 years ago Jun 13, 2019, 1:19 p.m. EDT

Hi Radu, A colleague of mine brought your comment to my attention. The variable is part of the Scharfetter-Gummel scheme used by the default finite volume discretization to compute the drift-diffusion current density. The formulation is complicated and it is impossible for us to document all the details. Nevertheless if you contact us at support@comosl.com and let us know what you would like to do, we may be able to provide some suggestions. Please do note that in general our support team can not help with any customized model with modifications to the Equation View. Sincerely, Chien

Hi Radu, A colleague of mine brought your comment to my attention. The variable is part of the Scharfetter-Gummel scheme used by the default finite volume discretization to compute the drift-diffusion current density. The formulation is complicated and it is impossible for us to document all the details. Nevertheless if you contact us at support@comosl.com and let us know what you would like to do, we may be able to provide some suggestions. Please do note that in general our support team can not help with any customized model with modifications to the Equation View. Sincerely, Chien

Please login with a confirmed email address before reporting spam

Posted: 5 years ago Jun 14, 2019, 7:21 a.m. EDT

Hi Radu, A colleague of mine brought your comment to my attention. The variable is part of the Scharfetter-Gummel scheme used by the default finite volume discretization to compute the drift-diffusion current density. The formulation is complicated and it is impossible for us to document all the details. Nevertheless if you contact us at support@comosl.com and let us know what you would like to do, we may be able to provide some suggestions. Please do note that in general our support team can not help with any customized model with modifications to the Equation View. Sincerely, Chien

Hi Chien. Thank you very much for the clarification! I have written a detailed email to the address you mentioned. Cheers!

>Hi Radu, A colleague of mine brought your comment to my attention. The variable is part of the Scharfetter-Gummel scheme used by the default finite volume discretization to compute the drift-diffusion current density. The formulation is complicated and it is impossible for us to document all the details. Nevertheless if you contact us at support@comosl.com and let us know what you would like to do, we may be able to provide some suggestions. Please do note that in general our support team can not help with any customized model with modifications to the Equation View. Sincerely, Chien Hi Chien. Thank you very much for the clarification! I have written a detailed email to the address you mentioned. Cheers!

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