Learning Forum

[Ralph Maru Grande]

What Ansys program is the most appropriate to use if I plan on desinging and modeling an LED and measure how its forward voltage and reverse current change as surrounding temperature changes? Does it provide stable bias current and voltage sources or will importing specific spice files for the sources be necessary?

[Guilin Sun]

This is a good question. LED is usually large compared to OLED. You did not mension the size. Here is just a brief introduction. For current and heat simulations, you can use CHARGE and HEAT. For the optics side, you can either use FDTD, or use stackdipole and stackpurcell functions:

stackdipole - Script command – Ansys Optics

stackpurcell - Script command 

FDTD vs stackdipole - halfspace emission in a multilayer stack

STACK GUI - OLED Device Introduction – Ansys Optics

STACK Optical Solver Overview – Ansys Optics

You will need to simulate saparately and with the results imported to FDTD.  You may first try to use HEAT,CHARGE and see if the large size device can be simulated. If FDTD is challenge, the scripts should work.

However, currently you may not directly use np density as index perturbation for the stack functions.

if needed  please file a feature request.  https://forum.ansys.com/forums/topic/vote-new-features-and-file-your-feature-request/#latest

If you are a commercial user, please contact sales for more support: https://www.lumerical.com/contact-us/find-a-local-rep/

[Ralph Maru Grande]

Thank you for your response, to clarify I plan on designing and modelling an LED whose size ranges 100um to 200um in diameter. Does that change the kind of software most appropriate for testing?

[Guilin Sun]

 

what is the total thickness ?is it also on the order of 100um? if so, FDTD can work but you may need a supercomputer. it may need hours for simulation. If you approximate it as a thin-film type, the analytical solution is much faster, within minutes. I personally would like to use the analytical solution,since only the edge part may not give the same contribution as the large central region, due to side wall reflection/refraction.

Please try to download FDTD, and run the analytical solution, as the scripts come with the software. You can also estimate the required memory under mesh accuracy 2 with FDTD so you will know more for the hardware. You have 30 days free trial.