Multiple exciton generation and subsequent electrical extraction from a thin film photoconductive device constructed from PbSe nanocrystal quantum dots are demonstrated. The hydrazine treatment of the PbSe film drastically improves the conductivity of the film while maintaining excellent optical and structural film quality. The effects of multiple exciton generation and electrical extraction (electrons collected per photon absorbed) were quantified as a function of incident photon energy from 1.55 to 3.1 eV. The multiple carrier extraction (>100%) was observed at photon energies greater than 2.8 times of the quantum dot bandgap with ∼210% measured at 4.4 times the bandgap.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)