Organometallic chemical vapor deposition and characterization of indium phosphide nanocrystals in Vycor porous glass

Indium phosphide has been deposited in 40 and 150 Å Vycor porous glass by the reaction of trimethylindium with excess PH3. X-ray diffraction (XRD) of the red, transparent samples confirms the presence of crystalline indium phosphide. The amount of III-V material deposited within the glass matrix (loading) and annealing conditions influence the crystallinity and particle size of the nanocrystallites. The absorption spectra of vacuum-annealed samples is blue shifted with respect to bulk InP, with maxima ranging from 500 to 700 nm for both the 40 and 150 Å samples and is consistent with size quantization. The nonlinear optical properties of these nanocrystallite composites have been evaluated by Z-scan measurements and are characterized by a defocusing refractive nonlinearity influenced by a substantial nonlinear loss presumed to be caused by two-photon absorption.