TEMPERATURE-DEPENDENT OPTICAL RESONANCES OF QUANTUM-CONFINED CUCL NANOCRYSTALS IN BOROSILICATE GLASSES

The optical density change of the CuCl-doped borosilicate glasses (2 w t% CuCl +52.5SiO(2)-40B(2)O(3)-7.5Na(2)O(wt%)) heat treated at 550 deg rees C for 0-10 hrs was measured with temperature at spectral vicinity of the CuCl resonant absorption and the effect of size and distributi on of CuCl precipitate particles on the optical spectra was investigat ed. The optical absorption spectrum obtained during heating and coolin g cycle showed a typical hysteresis loop because of the melting and so lidification of the CuCl particles embedded in the glass matrix. The s hape of the optical absorption curve measured at 375 nm with temperatu re upon melting of CuCl particles was dependent on the size and the di stribution of the CuCl particles. While the average size of the CuCl p articles increased with heat treatment time, the size difference of th e precipitated CuCl particles was found to be decreased with time befo re 1 h and then increased, The optical absorption spectra of the CuCl doped glass was also predicted theoretically and the predicted spectra curve was found to be in good agreement with experimental data. It is proposed that if the semiconducting particles embedded in an opticall y transparent matrix and the melting point of semiconductor is lower t han that of the matrix material, the average size and size distributio n of the particles can be estimated by the optical absorption measurem ents with temperature. (C) 1997 American Institute uf Physics.