Synthesis of InAs nanocrystals embedded in SiO2 glasses by a sol-gel process

InAs nanocrystals embedded in SiO2 gel - glasses were prepared by a sol - g el method. The gels synthesized through the hydrolysis of a complex solutio n of Si(OC2H5)(4), As2O3 and InCL3. 4H(2)O were heated at 450 degreesC in O -2 atmosphere, and then heated from 200 to 500 degreesC in H-2 atmosphere t o form fine cubic InAs crystals. The size of InAs nanocrystals, determined from the line broadening of X - ray diffraction pattern, increases from 6 t o 29 in diameter with heat - treatment temperature and molar ratio of InAs/ SiO2 increasing. The InAs nanocrystal was found to be a polycrystal in the gel - glasses by electron diffraction pattern.