Optical properties of PbS quantum dot doped sol–gel films

Abstract PbS nanoparticles have been prepared via a colloidal route and were incorporated in hybrid organic-inorganic sol–gel films. X-ray diffraction and transmission electron microscopy showed the presence of spherically shaped particles with nanometric diameter. The absorption spectra showed a large blue shift of the absorption edge to shorter wavelength, indicating strong quantum confinement. Strong photoluminescence emission in the near infrared was found by pumping at 514 nm. The femtosecond pump–probe technique was used for studying the relaxation dynamics of the PbS-doped films by pumping at 800 nm and probing at 1500 nm.