Guilin Sun
Ansys Employee

When the high field mobility  is enbaled, many a time the simulation can diverge, due to some reasons. I would suggest to read this article: https://optics.ansys.com/hc/en-us/articles/8355464963987-Troubleshooting-convergence-errors-in-CHARGE  It has some solutions for this case.

Have you tested zero bias? if it can run successfully, it means the field might be too high and finer mesh is needed.

When you sweep the voltage, please try to use smaller voltage step.

 

If the zero bias cannot converge, please first disable the high field mobility, and do a test. Then plot the fields and see where the high field is located. Then add "constraint" mesh to limit its largest edge length. Repeat the above tests again.