Laser thermal annealing effects on single crystal gallium phosphide

Pastor, David; Olea, J.; Toledano-Luque, M.; Mártil, I.; González-Dı́az, G.; Ibáñez, J.; Cuscó, R.; Artús, L.

doi:10.1063/1.3187902

Cited by 14 publications

(8 citation statements)

References 31 publications

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“…The important fact is that its intensity increases with annealing energy. This is a similar behavior as for InP layers after PLA, , and indicates the formation of polycrystalline GaMnP film with misoriented domains. The LO peaks of 0.50 and 0.60 J/cm 2 annealed GaMnP exhibit a downward shift to the left side when compared with 0.45 J/cm 2 annealed sample, arising from two effects: (1) the CPLOM appears and shifts the LO peak to lower frequency and (2) the presence of strain introduced by crystalline domain boundaries and defects.…”

Section: Resultssupporting

confidence: 75%

Ferromagnetic Mn-Implanted GaP: Microstructures vs Magnetic Properties

Yuan

Hübner

Liu

et al. 2016

ACS Appl. Mater. Interfaces

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Ferromagnetic GaMnP layers were prepared by ion implantation and pulsed laser annealing (PLA). We present a systematic investigation on the evolution of microstructure and magnetic properties depending on the pulsed laser annealing energy. The sample microstructure was analyzed by high-resolution X-ray diffraction (HR-XRD), transmission electron microscopy (TEM), Rutherford backscattering spectrometry (RBS), ultraviolet Raman spectroscopy (UV-RS), and extended X-ray absorption fine structure (EXAFS) spectroscopy. The presence of X-ray Pendellösung fringes around GaP (004) and RBS channeling prove the epitaxial structure of the GaMnP layer annealed at the optimized laser energy density (0.40 J/cm(2)). However, a forbidden TO vibrational mode of GaP appears and increases with annealing energy, suggesting the formation of defective domains inside the layer. These domains mainly appear in the sample surface region and extend to almost the whole layer with increasing annealing energy. The reduction of the Curie temperature (TC) and of the uniaxial magnetic anisotropy gradually happens when more defects and the domains appear as increasing the annealing energy density. This fact univocally points to the decisive role of the PLA parameters on the resulting magnetic characteristics in the processed layers, which eventually determine the magnetic (or spintronics) figure of merit.

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Section: Resultssupporting

confidence: 75%

Ferromagnetic Mn-Implanted GaP: Microstructures vs Magnetic Properties

Yuan

Hübner

Liu

et al. 2016

ACS Appl. Mater. Interfaces

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“…As it can be seen, there are not extended defects in the GaP substrate when the energy density is inside the window defined in the experimental section. This result is clearly different from the one reported in [17], in which a defective polycrystalline layer was produced when the energy density of the PLM process was very high (0.7 J/cm 2 and 1.2 J/cm 2 ). The high quality of the sample shown in the XTEM image of Fig.…”

Section: Resultscontrasting

confidence: 99%

On the properties of GaP supersaturated with Ti

Olea

Algaidy

Prado

et al. 2020

Journal of Alloys and Compounds

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We have fabricated GaP supersaturated with Ti by means of ion implantation and pulsed-laser melting to obtain an intermediate band material with applications in photovoltaics. This material has a strong sheet photoconductance at energies below the bandgap of GaP and it seems to be passivated by a Ga defective GaPO oxide layer during the laser process. Passivation is consistently analyzed by sheet photoconductance and photoluminescence measurements. We report on the structural quality of the resulting layers and analyze the energy of the new optical transitions measured on GaP:Ti. A collapse found in the sheet photoconductance spectra of GaP:Ti samples fabricated on undoped substrates is explained by the negative photoconductivity phenomenon.

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“…In previous studies, we concluded that melting and recrystallization processes under excimer laser radiation are not straightforward for GaP. It seems that for high recrystallization velocities, GaP is not able to regrow following the crystal structure of the underlying nonmelted substrate, and polycrystalline phases appear, though for high energy densities, the crystal quality and the size of the grains increased.…”

Section: Introductionmentioning

confidence: 84%

Strong subbandgap photoconductivity in GaP implanted with Ti

Olea

Prado

García-Hemme

et al. 2017

Progress in Photovoltaics

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Photovoltaic solar cells based on the intermediate band (IB) concept could greatly enhance the efficiency of future devices. We have analyzed the electrical and photoconductivity properties of GaP supersaturated with Ti to assess its suitability for IB solar cells. GaP:Ti was obtained by ion implantation followed by pulsed-laser melting (PLM) using an ArF excimer laser. It was found that PLM energy densities between 0.35 and 0.55 J/cm 2 produced a good recovery of the crystalline structure of GaP (both unimplanted and implanted with Ti), as evidenced by high mobility measured values (close to the reference GaP). Outside this energy density window, the PLM failed to recover the crystalline structure producing a low mobility layer that is electrically isolated from the substrate. Spectral photoconductivity measurements were performed by using the van der Pauw set up. For GaP:Ti a significant enhancement of the conductivity was observed when illuminating the sample with photon energies below 2.26 eV, suggesting that this photoconductivity is related to the presence of Ti in a concentration high enough to form an IB within the GaP bandgap. The position of the IB was estimated to be around 1.1 eV from the conduction band or the valence band of GaP, which would lead to maximum theoretical efficiencies of 25% to 35% for a selective absorption coefficients scenario and higher for an overlapping scenario.

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Laser thermal annealing effects on single crystal gallium phosphide

Cited by 14 publications

References 31 publications

Ferromagnetic Mn-Implanted GaP: Microstructures vs Magnetic Properties

Ferromagnetic Mn-Implanted GaP: Microstructures vs Magnetic Properties

On the properties of GaP supersaturated with Ti

Strong subbandgap photoconductivity in GaP implanted with Ti

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