Abstract: The studies were focused on the optical properties of supercritical-drying-technique-prepared silica
aerogels assembled with PbS colloids synthesized by colloidal chemistry route. Transmission electron microscope was used to image
the assembled samples. Fluorescence spectroscopy and absorption spectrophotometer were employed to investigate the optical properties
of the assembled systems. Large optical absorption edges red-shift along with the increase of annealing temperature was observed, which
can be attributed to the quantum confinement effects. Photoluminescence intensity enhances along with the increase of the annealing temperature
to the maximum at 573K, dropping thereafter, and the photoluminescence peaks show small red-shifts in the meanwhile. These phenomena are
related to quantum confinement effects, defect states in the particle surface and excitonic recombination probability.

Key words: meso-porous assemblies, aerogels, quantum confinement effect