Exciton zinc compounds

Table ir.l-IU Exciton binding energies of zinc compounds... 

In this chapter some of the presently known optical properties of zinc oxide are reviewed. In particular, the anisotropic dielectric functions (DFs) of ZnO and related compounds from the far-infrared (FIR) to the vacuum-ultraviolet (VUV) spectral range are studied. Thereupon, many fundamental physical parameters can be derived, such as the optical phonon-mode frequencies and their broadening values, the free-charge-carrier parameters, the static and high-frequency dielectric constants, the dispersion of the indices of refraction within the band-gap region, the fundamental and above-band-gap band-to-band transition energies and their excitonic contributions. 

A number of reports on phthalocyanines and porphyrins have been published. Spectral diffusion and thermal recovery of spectral holes burnt into phthalocyanine doped Shpol skii systems has been examined . An absorption, emission, and thermal lensing research on carboxylated zinc phthalocyanine shows the influence of dimerization on these properties. Fourier transformation of fluorescence and phosphorescence spectra of porphine in rare gas matrices has yielded much structural and electronic state data on this compound . Exciton splitting is an effect which is seen in the spectra of covalently linked porphyrins . A ps fluorescence study of the semirigid zinc porphyrin-viologen dyad has provided evidence for two dyad conformers . Spectral diffusion in organic glasses has been measured by observing the hole recovery kinetics over the time scale of 1 to 500 ms for zinc tetrabenzoporphyrin in PMMA . 

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