I am working on Perovskite solar cells, I want to make them in ambient conditions and probably I will not use a HTM.

Carbon has been used as a counter electrode as well as the HTM material in different combinations.

It has been used as a porous material that has the perovskite dropped through and also been used to paste on top as a cheap Dr blade system

I have various papers that I have checked.... for some you need to have zirconium pearl and to grind it with the carbon... I think the most convenient one is the one I saw with Carbon Graphite and the hot press with PVAc

http://www.sciencedirect.com/science/article/pii/S000862231500439X this seems the most convenient method.... they use a ball mill and hot press so some labs may not be able to repeat this although I guess a morter pestle would be similarly useful but probably noway near as effective and probably very messy and might stain the morter and pestle. (Hand using a hard rod and grind in a hard bowl basically)

to list the papers would be easy but to be clear how to get those carbon pastes and Dr Blade them is a lot harder than one might think.

I am assuming it is not simply conductive carbon ink. The solvents in these would destroy the perovskite. Some papers remove the carbon If you were to put the carbon in on a substrate the carbon comes off when you touch it. So I am a little confused as to the best way ahead on this issue considering I would like to buy cheap carbon paste to put on my perovskite solar cell but how cheap is 'cheap' and how commercial does commercial mean?

Does anyone else find the same issue as me... I think most of the suppliers are in china right? or are there a lot of european companies? I mean doing a Google and getting a clear price for something that a paper used and it is clear that is what they used is more complicated than i really expected.

Hope you are all well and if you celebrate Christmas that you have a lovely time. Also thanks in advance for bothering to read and possibly answer.

Harry