Comments

True, the Delaware team obtained over 40% efficiency, but their cell was a triple-junction device operating under concentrated light. I assume the author was referring to single-junction solar cells when he said 18-20% is currently the best we can do. The best commercial-grade silicon cells currently have efficiencies a little lower than this, so 18-20% is either for lab-grown silicon or commercial III-V single-junction cells. Also, the author says that these dye-sensitized cells have low efficiencies because of poor absorption. But, isn't the whole purpose of using various size balls to increase the amount of light absorbed by allowing the cell to absorb a wider portion of the light spectrum? I thought I heard somewhere that the reason these new organic, popcorn ball, or quantum dot cells are so inefficient is because of their high rate of recombination. I could be wrong, but I think recombination and absorption are completely different. Someone chime in if they can elaborate.