OPTICAL-PROPERTIES OF RANDOM AMORPHOUS MULTILAYERS A-SI-H A-SI3N4+X-H

Anomalous reflection peaks and dips have been observed in optical reflectance spectra of random amorphous multilayers made of a-Si:H/a-Si3N4+x:H. A model using the idea of localization of light propagation has been used to explain these anomalies. The localization length of light xi is estimated experimentally and by simulation in this random system. The distribution of electric field strengths E(2) in multilayers are calculated. The distribution of E(2) in random multilayers is quite different from that in superlattices which are the regular multilayers. It is found that the bandwidth of high reflection region is broadened by the randomization of the layer thickness in lambda/4 reflection multilayers made of a-Si:H/a-Si3N4+x:H. If these random amorphous multilayers are applied to design the structure of amorphous solar cells, there is a possibility to improve the efficiency by confining the light in cells.