Would elderberry extract/concentrate work? Can you mix it with anything to make it stronger?

I recently read your article on dye-sensitized solar cells while researching the topic. I am doing a similar experiment and was planning on using elderberry extract/concentrate (I am too young to buy the wine) to dye the solar cell. I am prohibited from using red cabbage or passion tea but I need to obtain the highest possible voltage value for my solar cell. If you have any suggestions on how to make the cell more efficient it would be greatly appreciated!

placeholder text for bug in Chrome