PHOTOLUMINESCENCE IN DOPING-MODULATED AMORPHOUS-SILICON MULTILAYERS

In order to study the relation of photoluminescence from amorphous nip i multilayers to the spatial separation of carriers, combined measurem ents of photo-induced electroabsorption and photoluminescence have bee n performed. A close correlation is found between the photoluminescenc e intensity and the change in optical transmission, the latter reflect ing the spatial separation of carriers. Furthermore, the photoluminesc ence from the nipi multilayers with a thin undoped sublayer has been e nhanced with an external electric field applied perpendicular to the i nternal electric field which works to prevent carrier separation. From these results, it is concluded that the carrier separation reduces ph otoluminescence from the amorphous nipi multilayers when the undoped s ublayer is thin.