i have made graphene counter for DSSC application and want to know the minimum characterizations in this regard.
What is Cyclic voltammetry? I mean what does it shows in CE regard? Please explain.
Also you can take XRD analysis, SEM, TEM, resistance measurements etc.
I suggest the electrochemical impedance spectroscopy, since it could directly show the interfacial charge transfer resistance, it is very useful for counter electrode. You can see literature:Electrochimica Acta 54 (2009) 5320-5325. Welcome for further discussion.
Sir in electrochemical impedance spectroscopy perhaps we need a source to illuminate our cell but we do not have this kind of arrangements on our system. So it will not important for dssc when done in dark...no.
If you have three electrode system, the working electrode, the counter electrode and a reference electrode then you can directly measure the I-V characteristics of the counter electrode. The ideal counter electrode must be ohmic with low resistance. If is rectifying with relatively large voltage drop, it does mean that your counter electrode needs to be improved. The I-V measurement can be undertaken by conventional measuring instruments. You need only a variable voltage power supply a current limiting resistance connected in series with the power supply and the device between the counter electrode and the working electrode . Then you measure the voltage between the the counter electrode and the reference electrode and measure the current in the counter electrode.. You need an ammeter and a voltmeter adjusted on the proper range.
Abdelhalim Zekry Sir, very much thanks for the suggestion. It means no illumination source is required for the dssc ;s impedence measurement. I can do it directly .
Yes Bulesh. The counter electrode has no light absorbing function as the working electrode. It t has only dark characteristics which means that it must conduct the cell current with negligible voltage drop to reduce losses in the solar cell. You can also make small signal impedance measurement with frequency which is called impedance spectroscopy. But you have normally to bias the electrode at certain DC current. So, in every case you have to bias the electrode with DC source.
wish you success
Thank you Sir for this valuable answer actually you have solved a big problem of mine. Otherwise i was thinking that without source i cant do this measurement. But what type of reference i need like Platinum counter electrode in dssc as it is ideally used in dsscs by whole world?
But i would like to ask you why can you not illuminate the solar cell.
The sources of illumination are very available. You can use quartz halogen lamps.
You can use also Power light emitting LEDs they give sufficient light with frequency spectrum to illuminate the working photo electrodes.
For the reference electrodes suitable with DSSCs please see the paper in the link:
http://www.elp.uji.es/paperspdf/2003%20JPCB%20ref.pdf
and the paper in the link:www.sciencedirect.com/science/article/pii/S0022072805006169
The reference electrode must sense the potential and acts as an Ohmic contact.
Wish you success
You could observe the morfology of your counter electrode using SEM before and after the use with electrolyte. Then you could measure the sheet resistance with the 4-probe technique. Other useful characterization is the electrochemical impedance spectroscopy with symmetric cell. the symmetric cell is a cell, like the DSSC, composed by two identical counter electrodes and filled with electrolyte. the Nyquist plot gives you information about the charge transfer resistance.
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