Raman spectroscopy of porous and bulk GaP subjected to MeV-ion implantation and annealing

Abstract

Ion channeling effects on quantum well intermixing in phosphorus-implanted InGaAsP ∕ InGaAs ∕ InP J. Appl. Phys. 98, 054904 (2005); 10.1063/1.2033143Structure-property relationships in porous GaN generated by Pt-assisted electroless etching studied by Raman spectroscopy J.Porous layers on ͑100͒-oriented n-type liquid encapsulated Czochralski grown GaP crystals were fabricated by electrochemical etching in a H 2 SO 4 aqueous solution and analyzed by scanning electron microscopy. 12 C ϩ ions were introduced at room temperature by 3 MeV energy implantation into porous and bulk samples at two ion doses of 10 14 and 10 15 cm Ϫ2 . The prepared samples were annealed in the temperature range between 200 and 600°C applying rapid thermal annealing ͑RTA͒ technique. A comparative micro-Raman study was carried out on the porous and bulk substances. Porosity was found to lead to the violation of the selection rules and to remarkable changes in the optical properties. Additionally, Fröhlich-type modes were observed in the Raman spectra of the porous layers. High energy implantation produces a thin high damaged layer, buried at the depth of the mean projected range. Implantation does not result in a drastic damage of the samples and they undergo a fast recovery after RTA. After this treatment a semi-insulating GaP layer is created, which is thermally stable up to 600°C.

Temperature-Dependent Photoluminescence Study of Porous Gap

“…The RS spectra (not shown) demonstrate the two peaks at around 365 cm -1 and peak at 404.2 cm -1 . The vibrational mode at around 365 cm -1 corresponds to TO phonon, while LO phonon vibration locates at 404.2 cm -1 , consistent with previous reports [9,[14][15][16]. It is important to note that the intensity of the scattering involving LO phonon in porous GaP is higher than that of bulk material and the LO-phonon peak is shifted to lower frequency (0.5 cm -1 ) and broadened with a low-frequency shoulder.…”

Raman-active modes of porous gallium phosphide at high pressures and low temperatures

“…Two bands labelled S1 and S2 are seen on the low-energy side of the bulk LO phonon (405.4 cm −1 ) in all three spectra. These bands have previously been studied both experimentally [14,15,21] and theoretically [16][17][18] and they have been attributed to the split Fröhlich modes in porous GaP. The S1 mode at the higher frequency was attributed to the transverse Fröhlich mode (FTO) and the S2 mode at the lower frequency to the longitudinal Fröhlich mode (FLO).…”

“…Porous GaP layers and free-standing membranes, in addition to powders, were used in investigations of Fröhlich mode behaviour [11][12][13][14][15]. Several theoretical calculations of these modes have dealt with the case of isolated particles [7][8][9][10].…”

Fröhlich modes in porous III-V semiconductors

“…Porous GaP (por-GaP) layers and free-standing membranes proved to be excellent materials to use to study the peculiarities inherent to porous III-V semiconductor compounds. Recent progress in the fabrication of por-GaP by electrochemical etching allows one to control and to reproduce properties of the porous structures such as the morphology and basic electrical parameters in a desired way [11][12][13][14]. An enhanced optical response, new radiation and scattering properties and Fröhlich modes have already been reported for several porous III-V semiconductors [15][16][17][18][19][20][21].…”