ZnO−TiO2 Core−Shell Nanorod/P3HT Solar Cells

We evaluate an ordered organic−inorganic solar cell architecture based on ZnO−TiO2 core−shell nanorod arrays encased in the hole-conducting polymer P3HT. Thin shells of TiO2 grown on the ZnO nanorods by atomic layer deposition significantly increase the voltage and fill factor relative to devices without shells. We find that the core−shell cells must be exposed to air to reproducibly attain efficiencies higher than 0.05%. Cells stored in air for 1 month are 0.29% efficient.