Hi Chitta,

I saw your question just now, I hope is not too late to answer :) 

This question is tricky one, due to the fact that the scientific community is mixing the concepts of Photopotential and Photovoltage, although they refer and describe different concepts.

The photopotential can be considered as the absolute difference between the OCP under illumination (steady state) and in the dark (steady state). Normally refers to the photopotential of your anode or cathode depending what your interest is, but more refers to the photoelectrode in question. Usually is measured in 3 electrode electrochemical cell. So what you refer is actually the photopotential. Your photoelectrode generates photopotenial under illumination (under OCP conditions), but this is not a photovolatege.

The photovolatage is the maximum bias attained by a two electrode solar cell working under illumination. So this is more a characteristic of a solar cell.

I hope this was clear for you and moreover all the best my friend!

I hope we publish something soon, although soon is relative term :) :).

If measured in a 3 electrodes cell, OCP is the potential of the photoelectrode measured vs. REF electrode. In this case OCP is not a voltage. If you need a voltage consider a voltage measurement between WORK and AUX. 

If measured in a 2 electrodes cell (anode-cathode), OCP is in fact emf (a voltage). 

OCP is developed when you immersed the electrodes in electrolyte, either three electrodes or two electrodes. This is the voltage obtained when the system at zero current. So, in two electrode system the OCP directly taking into account but three electrodes system, you need to measure voltage between working electrode and counter electrode. 

Hi Chitta,

I saw your question just now, I hope is not too late to answer :) 

This question is tricky one, due to the fact that the scientific community is mixing the concepts of Photopotential and Photovoltage, although they refer and describe different concepts.

The photopotential can be considered as the absolute difference between the OCP under illumination (steady state) and in the dark (steady state). Normally refers to the photopotential of your anode or cathode depending what your interest is, but more refers to the photoelectrode in question. Usually is measured in 3 electrode electrochemical cell. So what you refer is actually the photopotential. Your photoelectrode generates photopotenial under illumination (under OCP conditions), but this is not a photovolatege.

The photovolatage is the maximum bias attained by a two electrode solar cell working under illumination. So this is more a characteristic of a solar cell.

I hope this was clear for you and moreover all the best my friend!

I hope we publish something soon, although soon is relative term :) :).

Dejan Cibrev has offered a good explanation, particularly the difference between potential and voltage. To add to that, OCP exists disregarding if the electrode is in dark or under radiation (illumination), but the photopotential reflects the response of the electrode towards the radiation.