I would propose in order to be able to interpret the results and understand the behavior of the fill factor it is advisable to calculate:

- the dark minority current alone

- The dark majority current

- The total dark current

If he superposition is applicable for such solar cells, then the dark current will reflect all recombination activities.

This is one thing.

The other issue is that is very hard to believe that such low surface recombination velocity will affect the performance of the solar cells as it is expected that the majority carrier transport dominates as the recombination velocity decreases.

So, the above analysis are required to understand this behavior.

Best wishes

Abdelhalim Zekry

Dear Prof. Zekry,

Thanks for your reply. You are suggesting that the supoerposition of the dark minority current and majority current may not end up the same as total dark current in the simulation. If this is the case, the result it self maybe not right?

The other thing actually I notice that as SRV decreases (SRV=10cm/S below), the dark IV characteristics tend to be identical, while there is a dramatic change in the light IV characteristics as I attached above.

As you mentioned that when low SRV at the MS interface, the majority carrier transport dominates, so it should not be affecting the performance. In the silvaco, I have previously tried to differentiate the term SRV for electron (SRVn) and hole (SRVp). It is found in metal/n-Si structure, the change in the SRVp results in this drop in the FF and s-kirk. I further extract the drift and diffusion current compoent and found out that when SRVp is low (

I can not comment the results without having the the majority dark current and the majority dark current and the minority dark current. The recombination current can be due to volume and surface recombination current. May be when the surface recombination is getting low then the volume recombination may be enhanced.

So, the dark current may change at the low recombination velocity.

Best wishes.