Efficient photoconductive devices at infrared wavelengths using quantum dot-polymer nanocomposites

We report high photoconductivity and narrow luminescence in nanocomposites of PbSe quantum dots in a polymeric matrix. The nanocomposites are photoactive at infrared wavelengths with narrow emission bands, tunable with the quantum dot sizes. The quantum dots sensitize the polymer at distinct wavelengths across the infrared range between 800 nm and 2μm, by virtue of quantum-size effects. Photoconductivity measured in the nanocomposites results in a quantum efficiency of ∼3%, which is among the highest reported so far in this spectral range.