FORMATION OF NANOSCALE PHOSPHORUS COLLOIDS IN IMPLANTED SIO2 GLASS

Phosphorus ions were implanted to SiO2 glasses at an energy of 180 keV to doses from 3 X 10(15) to 5 X 10(17) ions/cm2 at room temperature. TEM observation revealed that amorphous red phosphorus (P(red)) colloid particles of 2-4 nm in diameter are precipitated in the substrates implanted to doses < 2 X 10(17) ions/cm2. Dissociation of the resulting P(red) into P2 molecules was observed by optical absorption measured at temperatures > 550-degrees-C. After once heating to approximately 600-degrees-C, the particle size of P(red) increased over two orders of magnitude and the optical band gap decreased from 2.5 eV to 2.2 eV, which is close to that of bulk P(red).