Abstract
To achieve efficient carrier extraction from nanocrystal quantum dots, we introduce a novel tandem cell device using PbSe nanocrystal quantum dots and a P3HT/PCBM bulk hetero junction cell. The device is fabricated using an all solution based process. The device consists of a hydrazine treated PbSe nanocrystal photoconductive film coupled to the P3HT/PCBM bulk hetero junction cell. In this work, the photocurrent from the PbSe nanocrystal photoconductive layer, and the role of carrier multiplication at UV wavelengths, is elucidated. By using light biased spectral response measurements, we successfully demonstrate an enhancement of quantum efficiency at photon energies greater than three times the bandgap of the PbSe nanocrystals. Additionally, this tandem structured device shows a self-passivation property that provides protection from UV irradiation to the underlying polymer cell.
