Porous Gallium Phosphide Research Articles

Poly(p-phenylene vinylene)/porous GaP composite materials

We report results obtained from physical characterization of thin composite films made by mixing poly(p-phenylene vinylene) (PPV) and porous gallium phosphide (GaP) particles with different GaP concentrations. Optical measurements including Raman, infrared and photoluminescence show that the GaP particles were progressively incorporated to the polymer film which fills the powder pores. The fabricated films possess properties of both materials with a weak contribution of GaP to the optical properties, the main interaction effect consists in a blue shift in the emission spectra of PPV. Diodes using composites as an active layer exhibit higher conductivity than that of PPV, leading to an enhancement of the light emission. The improvement in optical and electrical performance of the composite based light emitting diodes (LEDs) makes this new composite a good candidate for display applications.

Temperature dependence of Raman scattering in porous galliumphosphide

Porous layers fabricated by electrochemical anodization of (111)A-orientedn-GaP:Te substrates were studied by Raman scattering spectroscopy in thetemperature interval from 10 to 300 K. Along with the transverse-optical (TO)and longitudinal-optical (LO) modes, the RS spectra of porous layers showFröhlich-type vibrations located in the frequency gap between the bulkoptical phonons. A longitudinal-transverse splitting of these surface-relatedvibrations was evidenced at low temperatures. Apart from that, the porouslayers prepared on highly doped substrates were found to showLO-phonon-plasmon coupled (LOPC) modes in the whole temperature intervalstudied. Observation of LOPC modes at low temperatures is explained takinginto account that the GaP skeleton consists of both depleted surface layerssurrounding the pores and conductive regions. The free electrons in theseregions, originating from the impurities actually located in the depletionlayers, are shown to be subject to spatial confinement increasing withdecreasing temperature.

Ion implantation of porous gallium phosphide

The effect of irradiation by Ar ions and thermal annealing on the properties of porous gallium phosphide (por-GaP) obtained by electrolytic methods is investigated. It is shown on the basis of Raman scattering and photoluminescence data that, in contrast with porous silicon, por-GaP does not have high radiation hardness, and that thermal annealing of defects in layers amorphized by ion implantation is impeded by the absence of a good crystal base for solid-state epitaxial recrystallization processes. Data on radiation-induced defect formation and from probing of the material with a rare-earth “luminescence probe” are consistent with a mesoporous structure of the material.

Ion implantation as a tool for controlling the morphology of porous gallium phosphide

We investigate the morphology of porous layers obtained by electrochemical anodization of (100)-oriented n-type GaP substrates before and after a preliminary 5-MeV Kr+ implantation. Apart from favoring the observation of a surface-related phonon in the frequency gap between the bulk optical phonons, ion implantation appears to be an effective means of controlling the morphology of porous GaP, irrespective of initial substrate material features.

Electrochemical formation and optical properties of porous gallium phosphide

Electrochemical formation and optical properties of porous gallium phosphide