Hello everyone!
I'm struggling to improve my natural DSSC. Could anyone give me a hint? What am I doing wrong here? My parameters and characteristics below. Picture of one of my cells attached.
Photo-anode: ITO-Glass (Ossila) + TiO2 T/SP paste (Solaronix)
Dye: Blackberry (Blend of 100g fruit + 100ml Ethanol)
Electrolyte: Iodolyte AN-50 (Solaronix)
Separation gasket: Parafilm with an opening over active area
Cathode: ITO-Glass (Ossila) + Pt Platisol T/SP paste (Solaronix)
Contacts: Electrical connection legs - 6 each side (Ossila)
Substrates cleaning: Detergent solution, acetone and ethanol (10 min each)
Sensitizing: 1h in ambient temp. (already tried more time but results were worse)
Sintering: 125ºC/ 30min + 500ºC/40min (both electrodes together)
TiO2 deposition: Screen printing 60 threads/cm (already tried 77 and 44, worse results)
Pt deposition: Doctor blade using microscope slide + mask with 2 layers of scotch tape
Sealing: Press sandwich (parafilm) over hotplate (50ºC/30sec)
Not using TiCl4 treatment yet.
Voc = 0.543V
Jsc = 0.473mA/cm2
FF = 62.37%
Efficiency = 0.16%
I read some papers with much better results.
Thank you!
Dear Marcelo Alatzatianou Rodrigues
Please read the following papers, you will get idea about improvement in current thru electron-hole concentration and transportation without recombination.
Dear Suraj,
I am reading lots of papers to find the problem. Your suggestions will definitely help me to go deeper. Thank you very much!
From the practical point of view, since most papers does not present details of the procedures, specially for natural dyes (Blackberries), did you find anything wrong in the way I am fabricating my cells?
Thanks again!
All the best,
Marcelo.
Dear Marcelo,
What I had observed in your steps (protocol) that you are anneaaling the sample at 500 deg. cent. after sensitization. If so, then most of the dye molecules will be removed, resulting in low current!
Are you annealing at 500 deg. cent. after the sensitization using dye?
Dear Suhail,
Thanks for your message.
No, the 500C step is before the sensitizing step, so the dye is not affected.
All the best,
Marcelo
Maybe someone finds the same difficult in the future, so I will keep this question posted.
Today the performance was much better:
Voc = 0.562V
Jsc = 0.492mA/cm2
FF = 74.40%
Eff. = 0.21%
The substrate was changed from ITO to FTO (both from Ossila). The difference between the substrates was already studied by Qiao et al. doi:10.1016/j.solmat.2005.05.020
Dear Marcelo,
You can try N719, N3 etc. dyes instead of berry dyes.
Thank you
With Best Wishes
Suhail
Suhail,
Thanks for the suggestion. I intend to use N719 for comparison, but my thesis is focused on natural dyes. That's why I am using Blackberries to start.
All the best!
Suhail,
My understanding is that, fruit as a whole contains proteins and vitamins, I guess this might reduce the current. So just try using the peel of the fruit to synthesize your dye.
Dear Vishesh,
Thank you for your contribution.
Since blackberries are pretty hard to peel off, because they are formed by several small parts, I decided to improve filtration and add a centrifugation step.
I also reviewed the technique of TiO2 film deposition. I studied diffrent meshes for screen printing available in my country and ordered some screens to find the best result.
With these 2 steps I could improve the efficiency a little bit again. These are my best parameters so far:
Voc = 0.563V
Jsc = 0.571mA/cm2
FF = 73%
Eff. = 0.23%
TiCl4 treatment was not used yet since this product is difficult to purchase here.
All the best,
Marcelo.
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