Optical Generation and Mesh settings of FDTD & DEVICE


I have a solar cell structure to which I need to import the optical generation from FDTD. I noticed that meshing properties are different between FDTD and DEVICE. So, I would like to know how optical generation data is embedded into the mesh in DEVICE environment. I know that in FDTD, calculated solar generation is interpolated to mesh nodes.

  • So, if we have a different mesh accuracy in DEVICE, would it still work ?

  • What are the important aspects to take into account regarding the mesh settings of both solvers?

  • How can I make sure that imported optical generation works correctly ?



FDTD Solutions is based on finite-difference time domain method and its mesh grid is retagular; while DEVICE is based on finite-element method. The default is triangular grid. Such difference must introduce some errors, which cannot be avoided.

To answer your questions:

  1. According to my experience, if the mesh sizes in FDTD and DEVICE are different, the program can still run. But if there is a large difference in mesh size, the Jsc calculated from DEVICE will be larger than that calculated from FDTD. That is incorrect. In this case, you should minimize the mesh size in both FDTD and DEVICE until you get smaller Jsc from DEVICE than that from FDTD.
  2. I think setting the mesh grid as small as possible can help you obtain the most accurate simulation results. Of course, this will increase memory and time consumption.
  3. Apart from the above two points, you can also check the log file which is generated when you run a DEVICE file. If there is no warning, in most cases, this indicates a good element setting.

Hope the above information helps.



Your remarks have been very helpful. Thank you !

You are welcome :slight_smile: