Good question

Good question

Dear Alemayehu Waketola , FDTD software packages can allow you to simulate that system, but as clearly stated by Mahdi Javidnasab it would be a lot easier to do so with monodisperse particles (same size and shape) and when they are distributed in a homogeneous way into the solar cell medium. It doesn´t mean that simulation of a very complex system would be possible, in fact it is, but at a high computational and design cost. You would have to describe a significative fraction of your solar cell, that in a polydisperse and inhomogeneous system would be quite large. In that volume you would need know where your particles are (their spatial coordinates), the size, shape and orientation of each particle and their composition, and of course the properties of the embedding medium. That could be probably houndred or thousands of particles to simulate and compute, so design time from your side and computational time from the computer.

Of course you can think that reducing the representative volume element would reduce the costs, and it is true, but your estimation would be far from the real thing.

FDTD works fine (simulation results are closer to experimental ones) when you have very regular distributions of structures, because that simplifies the calculations and reduce both design and computational costs due to symmetry effects.

So I agree Mahdi Javidnasab , you probably should try to simply your system to get an estimation, that you can improve by comparing your FDTD results with those obtained experimentally.

Note: imagine you have the patience to design a large number of particles with their varied sizes, shapes, orientations, separations and distances among them, a volume that you believe it respresent your cell. It will be a large task for the computer, but finally you get a result.... and when you make the experiments with a real solar cell you get that experiment an simulation don´t match.... what could happens easily, if the volume you choosed is not really representative of the whole cell. Making changes here would require a lot more effort than with simplified systems.

Hope it helps, but may be you can contact with the technical support crew of Lumerical for help.