I recently ran into this paper which describe experiments that confirm that hemoglobin is photoconductive. Finding this fact as incredible, I wanted to read up more on photoconductive properties of hemoglobin. The paper does not discuss what the conductivity number is, that would give some estimate of charge carrier density created when hemoglobin is illuminated. Do you have any estimates of how conductive hemoglobin gets? Is it close to highly doped semiconductors? Also, if you can provide links to papers that discuss more on photoconductivity of hemoglobin, that would be appreciated, as Google only showed me this sole paper from 1963.