Jt. Herrold et Vl. Dalal, Growth and properties of microcrystalline germanium-carbide alloys grown using electron cyclotron resonance plasma processing, J NON-CRYST, 270(1-3), 2000, pp. 255-259
We report on the growth and properties of a new material, microcrystalline
(Ge, C), which has potentially important optical, electrical and structural
properties. The material was grown using a remote, low pressure electron c
yclotron resosnance (ECR) plasma process on glass, stainless steel and c-Si
substrates. The growth was done with hydrogen dilution and ion bombardment
at temperatures of 350-400 degrees C. We discovered that the optical absor
ption curve parallels that of c-Ge, with increased bandgaps as C is incorpo
rated. We obtained up to 2% C incorporation, which increased the gap to 1.1
eV. At comparable bandgaps, the absorption coefficient of the (Ge, C) mate
rial is much larger than that of c-Si. Raman and X-ray measurements detecte
d microcrystalline structure, and a dependence of grain size on the substra
te used. The lattice constant contracted with C incorporation, approximatel
y obeying Vegard's law. Both undoped and n-doped materials were grown. (C)
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