PbS quantum dot electroabsorption modulation across the extended communications band 1200–1700nm

We report electric field-induced modulation of absorption in PbS nanocrystal quantum dots across the spectral region 600–2000nm, encompassing the entire telecommunications band. The maxima in the electroabsorption spectra correspond with the positions of the first excitonic peak, confirming the predominance of excitonic broadening as the basis for the observed effect. We estimate the change in dipole moment to be on the order of 20 D in 7nm diameter PbS nanocrystals compared to previously-reported ∼100D in CdSe.