ELECTROLUMINESCENT PROPERTIES OF A-SIOX-H ALLOYS

We report on a study of electroluminescence of p-i-n structures fabric ated from a substoichiometric hydrogenated amorphous silicon-oxygen al loy with oxygen content similar to 15 at.%. The devices exhibit a rect ification ratio of four orders of magnitude and emit electroluminescen ce under forward bias. The electroluminescence external quantum effici ency at T = 295 K is of the order of 10(-6)%. Analysis of thermal quen ching of photoluminescence and electroluminescence in the temperature range 100-480 K, combined with picosecond optical pump and probe measu rements, indicate contributions of molecular-like silicon structures a nd of electron-hole recombination in the band tail states to the proce ss of light emission at room temperature. (C) 1998 Elsevier Science B. V. All rights reserved.