I would like to congratulate you for this result. It would be better to depict the I-V curve. It is more expressive. I find the values which you give for the solar cell parameters are promising and good to start with.
I see that the main deficiency in your cells is the relatively high series resistance which caused the fill factor to be too low. You have to investigate the origin of your high series resistance. It is normally the bulk resistances of the semicondcutor layers. Contact resistances of the metallization layers.
I think you have solved this problems in the mean time as my answer came late.
I would like to congratulate you for this result. It would be better to depict the I-V curve. It is more expressive. I find the values which you give for the solar cell parameters are promising and good to start with.
I see that the main deficiency in your cells is the relatively high series resistance which caused the fill factor to be too low. You have to investigate the origin of your high series resistance. It is normally the bulk resistances of the semicondcutor layers. Contact resistances of the metallization layers.
I think you have solved this problems in the mean time as my answer came late.