OBSERVATION OF ANOMALOUSLY POLARIZED PHOTOLUMINESCENCE IN ALTERNATINGNANOCRYSTALLINE SI-AMORPHOUS SI MULTILAYERS

Polarization properties of visible photoluminescence (PL) from alterna ting hydrogenated nanocrystalline silicon-amorphous silicon multilayer s excited with linearly polarized light are examined. The PL is almost linearly polarized in the direction perpendicular to the polarization of excitation light, independent of the sample orientation. The degre e of linear polarization delta negatively increases with decreasing em ission energy, reaching a maximum of similar to 90% on the low-energy side, and a different temperature dependence is observed. In addition, it was found that the sample with large structural inhomogeneity disp lays low PL efficiency and large delta. Since the obtained PL spectra show no crystallite size dependence of the peak energy and fine struct ures, we attribute these anomalous polarization properties to the radi ative recombination of carriers confined in the interfacial region of optically anisotropic and randomly distributed Si:H nanocrystals. [S01 63-1829(98)06112-8].