DETERMINATION OF INHOMOGENEOUS CHARACTER OF OPTICAL-TRANSITIONS IN CDSSE SEMICONDUCTOR NANOCRYSTALS AT BAND-EDGE AT 300 K

The incoherent broad-band time delayed four-wave-mixing technique was used to study carrier relaxation dynamics at the absorption edge of Cd SSe nanocrystallites doped in glass at room temperature, The absorptio n spectra is found to be homogeneously broadened at shorter wavelength s and inhomogeneously broadened at longer. We find the ''homogeneous'' T-2 congruent to 30 fs throughout while the ''inhomogeneous'' T-2 mu ch greater than T-2 at the short wavelength end and approximate to T-2 at the long wavelength end where it corresponds to an inhomogeneous d istribution with a FWHM of 46 meV.