Nitrogenio em semicondutores amorfos

AUTOR(ES)
DATA DE PUBLICAÇÃO

1995

RESUMO

This work presents experimental data referring to the effects resulting from the introduction of nitrogen into amorphous silicon and germanium. AlI the samples studied in this work were deposited as thin films using the rf reactive sputtering technique in highly controlled Ar+(H2)+N2 gaseous atmospheres. It is shown that either the nitrogen presence and its content (as determined from nuclear reaction analysis measurements) are responsible for profound changes in several opto-electronic properties as well in the structure of the mentioned semiconductors. Roughly, nitrogen at low concentration levels acts as a donor-like impurity in both hydrogenated a-Si and a-Ge. High nitrogen contents, on the other hand, induce significant modifications in their optical band-gap and network structure. Different spectroscopic methods (optical absorpion, infra-red, Raman scattering and photoemission) were employed to analyze the main optical and electronic properties of these nitrogen containing semiconductors. Special emphasis was devoted to the electronic characterization, including transport measurements (dc dark conductivity as a function of temperature) and photoemission studies by means of x-ray and ultraviolet photoelectron spectroscopies (XPS and UPS, respectively)

ASSUNTO(S)

semicondutores amorfos filmes semicondutores compostos nitrogenicos

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