{"id":312436,"date":"2023-10-20T03:14:11","date_gmt":"2023-10-20T03:14:11","guid":{"rendered":"\/forum\/forums\/topic\/diverge-problem\/"},"modified":"2023-10-20T03:14:11","modified_gmt":"2023-10-20T03:14:11","slug":"diverge-problem","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/diverge-problem\/","title":{"rendered":"Diverge problem"},"content":{"rendered":"

Hello,<\/p>\n

I’m running simulation with a stack consists of metal-semiconductors-metal to see charge behavior. <\/p>\n

Applied bias from 0 V to -20 V on the one metal(gold) end, and GND(i.e., 0 V) to the other metal end. <\/p>\n

It was reverse bias, so I set the solver type as ‘gummel’.  <\/p>\n

Voltage step was -0.1 V, range backtracking is enabled.<\/p>\n

And it took 2 days to get – 3.75 V with error message as below:<\/p>\n

=========================================================================================<\/p>\n

Solver terminated at step 42 of 40.  Error  (charge): Drift-diffusion Newton solver failed to converge after 40 iterations.
Device solution update error ratio norm is 1.92713e+11
Device residual norm is 2.93284e-51.
Residual ratio (last iteration\/first iteration) is 7.43227e-11.<\/p>\n

Warning: The charge transport solver failed to converge (Charge Convergence Failure). A partial result will be saved. For instructions on how to troubleshoot this issue, please refer to this: <a href=”https:\/\/kb.lumerical.com\/redirect\/charge-convergence-error.html”>online reference<\/a>
The program terminated due to an error: The simulation diverged and the result is incomplete.
Error: there was an unknown parallel error. The error code is 9002, the process number is 0<\/p>\n

=========================================================================================<\/p>\n

From CHARGE monitor, I was looking at ‘n’ attribute, there’s fast depletion of electron density at the early stage of bias increase, as expected and attached images.<\/p>\n

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But my question is..<\/p>\n

Whether the solver diverged at -3.75V since it reached extreme depletion and there’s nothing solver can do about it anymore? <\/p>\n

.. or it is due to solver setting problem, like one in this article<\/a>?  <\/p>\n

From your professional point of view, I’d be really glad if you give me a hint. <\/p>\n

 <\/p>\n

Thanks,<\/p>\n

Sungmin <\/p>\n

 <\/p>\n

 <\/p>\n","protected":false},"template":"","class_list":["post-312436","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["27378","3002"],"_bbp_author_ip":["23.52.43.81"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["827"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["312436"],"_bbp_forum_id":["27833"],"_bbp_engagement":["3002","27378"],"_bbp_voice_count":["2"],"_bbp_reply_count":["2"],"_bbp_last_reply_id":["313404"],"_bbp_last_active_id":["313404"],"_bbp_last_active_time":["2023-10-26 04:16:26"]},"test":"sungmin-yoonkaist-ac-kr"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/312436","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/312436\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=312436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}