Polystyrene templated porous titania wells for quantum dot heterojunction solar cells.

Cheng C, Lee MM, Noel NK, Hughes GM, Ball JM, Assender HE, Snaith HJ, Watt AAR

Polystyrene spheres are used to template TiO2 with a single layer of 300 nm wells which are infilled with PbS quantum dots to form a heterojunction solar cell. The porous well device has an efficiency of 5.7% while the simple planar junction is limited to 3.2%. Using a combination of optical absorption and photocurrent transient decay measurement we determined that the performance enhancement comes from a combination of enhanced optical absorption and increased carrier lifetime.