Picosecond studies of electron confinement in simple colored glasses

Time-resolved optical measurements at low temperatures reveal finite size effects for excitons trapped in semiconductor microcrystallites embedded in a simple borosilicate glass. The excitation lifetimes are significantly shorter than those in comparable bulk material, with a marked dependence on crystallite size. The results are interpreted as an effect of three-dimensional confinement with]] box" dimensions comparable to the exciton diameter.