Efficient photodetection at IR wavelengths by incorporation of PbSe-carbon-nanotube conjugates in a polymeric nanocomposite

The investigation of the photodetection efficiency of a polymeric nanocomposite containing IR-active PbSe quantum dots (QD) and conducting single walled carbon nanotube (SWNT) is discussed. A stable SWNT PbSe conjugate is efficient for the realization of efficient optoelectronic behavior. Efficient dissociation and charge transfer depends on the differences in the potential energy and electron affinity between the photoactive species and the other components. The transfer of photogenerated holes to the polymer also proceeds without the requirement for any activation energy, as the ionization potential of the polymer lies closer to value for a vacuum than that of the QDs. Transmission electron microscopy (TEM) images of the SWNT-PbSe conjugate shows that a large number of PbSe QDs bind to the terminal thiol groups of the SWNTs. Efficient charge separation and transport is achieved by incorporating SWNT-PbSe conjugates, in which the QDs are attached to the nanotubes.