Optical properties of PbS quantum dot doped sol-gel films

PbS nanoparticles have been prepared via a colloidal route and were incorporated in hybrid organic-in organic sot-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 514nm. The femtosecond pump-probe technique was used for studying the relaxation dynamics of the PbS-doped films by pumping at 800nm and probing at 1500nm. (C) 2004 Elsevier B.V. All rights reserved.