Photoelectrochemical performance of CdSe nanorod arrays grown on a transparent conducting substrate.

Perpendicularly aligned semiconducting CdSe nanorod arrays were fabricated on ITO-coated glass substrate using porous aluminum oxide (PAO) as a hard template. Nanorod lengths were varied between 50 and 500 nm, while keeping the diameter at 65 nm. The electrochemical photovoltaic performance was found to depend critically on nanorod length and crystallinity. Arrays of rods annealed at 500 degrees C showed an order of magnitude improvement in white light power conversion efficiency over unannealed samples. The largest power conversion efficiency of 0.52% was observed for nanorods 445 +/- 82 nm in length annealed at 500 degrees C. The technique described is generally applicable to fabricating highly aligned nanorods of a broad range of materials on a robust transparent conductor.