Photoelectrochemical Charge Transfer Properties of Electrodeposited CdSe Quantum Dots

The blue shift in the optical band gap of CdSe quantum dot films was measured using liquid-junction photoresponse spectroscopy and correlated to nanocrystalline dimensions measured by transmission electron microscopy and X-ray diffractometry. Differences in the internal collection efficiency from films of various thicknesses are discussed in terms of both charge and energy transfer mechanisms. Pronounced sub-band-gap signals from intra-band-gap states have been observed. Features in the short wavelength region of the spectra have been attributed to charge transport involving hot holes.