ULTRAFAST PHOTOINDUCED ABSORPTION DYNAMICS OF CDS0.4SE0.6 NANOSTRUCTURE SEMICONDUCTORS DOPED IN GLASS

Ultrafast phenomena of photoinduced absorption far below the band gap of CdS0.4Se0.6 nanostructure semiconductors doped in glasses were inve stigated by using time-resolved differential transmittance spectroscop y. The carriers populating the semiconductor-glass interfaces within l ess than 1 ps after photoexcitation give rise to ultrafast photoinduce d absorption. This transient photoinduced absorption decays with a lif etime shorter than 10 ps, which strongly depends on the excitation int ensity. We assign this behavior to nongeminate electron-hole recombina tion at the semiconductor-glass interfaces. (C) 1998 Elsevier Science B.V. All rights reserved.