Amorphous arsenic chalcogenide films modified using rare-earth complexes

The optical and electrical properties of thin arsenic chalcogenide As-X (X=S, Se) films modified by rare-earth complexes with organic mixed-ligands have been studied. There were two types of complexes used: europium dipivaloylmethanate Eu(thd)(3) and lanthanide diethyldithiocarbamates Ln(ddtc)(3) (Ln=Pr, Eu). It was shown that the use of rare-earth mixed-complexes with neighbor volatility to chalcogenide volatility permits the deposition of amorphous films by thermal evaporation. The decrease in absorption coefficient at the Urbach's edge after introduction of the complexes containing oxygen in arsenic selenide has been revealed. The type of organic ligands incorporated in amorphous matrix determinates the shape of current-voltage characteristic. Such complexes decrease considerable the activation energy for electrical conduction as well. The observed results have been discussed on the basis of different levels of structural modification in non-crystalline materials.