Learning Forum

[Yanran Xie]

Hello! I am having trouble using the temperature monitor in CHARGE. I would like to calculate the temperature in a detector in operation.

I started with the avalanche detector example and basically added a temperature monitor that is within the same plane as the simulation region. However the temperature monitor has no output, nor can I export any result into a .mat file. I understand that "This monitor will only record data when performing non-isothermal or coupled (electro-thermal) simulations with the CHARGE solver", but I believe this is an electro-thermal simulation.

Any help will be appreciated. Thanks!!

 

[Khashayar Ghaffari]

Hi,

Thank you for posting your question. Have you changed your temperature mode in the CHARGE settings? As indicated by the error to record thermal data with the monitor, the simulation has to be set to *coupled. This setting is available in the general tab of the CHARGE solver. Alternatively, you may decide to use the HEAT solver for your analysis.

Best regards

[Yanran Xie]

Thank you for the reply. The mode is set to non-isothermal (see below screenshot), and there is still no output from the temperature monitor. It might be worth mentioning that the simulation is cut off after breakdown is reached, as per the instruction in this page (https://optics.ansys.com/hc/en-us/articles/360042454814). If I set the mode to coupled the simulation would not run. Meanwhile, the setup in HEAT would not allow me to input light source or apply voltage (voltage bondry condition is greyed out). 

[Khashayar Ghaffari]

Sorry I need to make a correction to my previous comment: The thermal mode needs to be set to coupled for the temperature monitor to record any heating. This is because non-isothermal mode, heating is not simulated; this mode is helpful for importing spatial temperature map. More information on the thermal mode is provided here. 

Obtaining convergence in coupled mode, is indeed more difficult since the solution becomes more complex. We don’t have an online example for coupled Avalanche Detector simulation. To troubleshoot the error, I recommend testing the behavior for smaller bias voltages and fewer steps (e.g. 0, -0.5, and -1V) to see if convergence can be obtained at all. Adjusting some of the advanced settings might be helpful. More information for addressing convergence issues is mentioned here.

As you suggested, the convergence error at breakdown voltage is normal. 

I will update my previous comment to include the correct information about CHARGE thermal modes.

Best regards