Photoluminescence, structural and electrical properties of passivated a-Si:H based thin films and corresponding solar cells

This paper deals with the photoluminescence, structural and electricalproperties of chemically passivated a-Si:H basedthinfilms and correspondingthinfilmsolarcells. The structures were chemically passivated in three types of KCN and HCN solutions containing MeOH and/or with water. The photoluminescence measurements were performed at 6 K using Ar laser and lock-in signal recording device containing Ge and Si photodetectors. Optically determined band gap related photoluminescence signals were observed between 1.1 and 1.7 eV. The electricalproperties were measured by a high-sensitive charge version of deep level transient spectroscopy (Q-DLTS). The evolution of three basic groups of defects was observed. The structural studies were realized by the standard X-ray diffraction analysis. The cyanide treatment improved significantly the electrical characteristics of both corresponding MOS structures and solarcells due to the passivation of some parts of the dangling bonds by CN group. Particularly, the passivation of the defects at interfaces in MOS or solarcell multilayer structures was achieved which is of primary practical importance.