|
|
Creator | Title | Description | Subject | Date |
1 |
|
Scarpulla, Michael | Effects of pressure on the band structure of highly mismatched Zn1-yMnyOxTe1-x alloys | We report photomodulation spectroscopy measurements of the pressure dependence of the optical transition in Zn12yMnyOxTe1-x alloys that is associated with the lowest Ѓ conduction band (termed E2 subband). The pressure-induced energy shift of the E2 transition is nonlinear and much weaker as compare... | Highly mismatched alloys; Zinc telluride; Anticrossing | 2004 |
2 |
|
Scarpulla, Michael | Enhanced nitrogen incorporation by pulsed laser annealing of GaNxAs1-x formed by N ion implantation | We demonstrate that pulsed laser annealing followed by rapid thermal annealing greatly enhances incorporation of substitutional N in N1-implanted GaAs. Films implanted to 1.8% N exhibit a fundamental band gap of 1.26 eV (a band gap reduction of 160 meV), corresponding to an N activation efficiency ... | Highly mismatched alloys; Gallium arsenide | 2002 |
3 |
|
Scarpulla, Michael | Mutual passivation of group IV donors and nitrogen in diluted GaNxAs1 x alloys | We demonstrate the mutual passivation phenomenon of Ge donors and isovalent N in highly mismatched alloy GaNxAs1-x doped with Ge. Layers of this alloy were formed by the sequential implantation of Ge and N ions followed by pulsed laser melting and rapid thermal annealing. The mutual passivation effe... | Highly mismatched alloys; Passivation; Gallium arsenide | 2003 |
4 |
|
Scarpulla, Michael | Mn L3,2 x-ray absorption spectroscopy and magnetic circular dichroism in ferromagnetic Ga1-xMnxP | We have measured the X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) at the Mn i32 edges in ferromagnetic Ga1-xMrixP films for 0.018<x<0.042. Large XMCD asymmetries at the L3 edge indicate significant spin-polarization of the density of states at the Fermi energy. The spectral s... | X-ray absorption; Ferromagnetic semiconductors; X-ray magnetic circular dichroism (XMCD); Gallium Manganese Phosphide; Gallium arsenide | 2007 |
5 |
|
Scarpulla, Michael | Diluted II-VI oxide semiconductors with multiple band gaps | We report the realization of a new mult-band-gap semiconductor. Zn1-yMnyOxTe1-x alloys have been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of ... | Highly mismatched alloys; Zinc telluride | 2003-12 |
6 |
|
Scarpulla, Michael | Synthesis and optical properties of II-O-VI highly mismatched alloys | We have synthesized ternary and quaternary diluted II-VI oxides using the combination of O ion implantation and pulsed laser melting. CdOxTe12x thin films with x up to 0.015, and the energy gap reduced by 150 meV were formed by O1-implantation in CdTe followed by pulsed laser melting. Quaternary Cd0... | Highly mismatched alloys; Cadmium telluride; Zinc telluride; Thermal annealing; Anticrossing; Photomodulation spectroscopy | 2004 |
7 |
|
Scarpulla, Michael | Synthesis and properties of highly mismatched II-O-I alloys | Ternary and quaternary dilute II-VI oxides were synthesised using a highly nonequilibrium method: the combination of O ion implantation and pulsed-laser melting. CdOxTe12x thin films have been produced with x up to 0.015 and with the energy gap reduced by 0.15 eV. Optical transitions corresponding t... | Highly mismatched alloys; Cadmium telluride; Zinc telluride; Anticrossing | 2004 |
8 |
|
Scarpulla, Michael | Mn L3,2 x-ray absorption and magnetic circular dichroism in ferromagnetic Ga1-xMnxP | We have measured the x-ray absorption and x-ray magnetic circular dichroism (XMCD) at the Mn L3,2 edges in ferromagnetic Ga1−xMnxP films for 0.018≤x≤0.042. Large XMCD asymmetries at the L3 edge indicate significant spin polarization of the density of states at the Fermi energy. The temperatur... | X-ray absorption; Gallium Arsenide; Ferromagnetic semiconductors | 2006 |
9 |
|
Scarpulla, Michael | Synthesis of GaNxAs1-x thin films by pulsed laser melting and rapid thermal annealing of N+-implanted GaAs | We present a systematic investigation on the formation of the highly mismatched alloy GaNxAs1-x using N1-implantation followed by a combination of pulsed laser melting and rapid thermal annealing. Thin films of GaNxAs1-x with x as high as 0.016 and an activation efficiency of the implanted N up to 5... | Highly mismatched alloys; Gallium arsenide | 2003 |
10 |
|
Scarpulla, Michael | Heat flow model for pulsed laser melting and rapid solidification of ion implanted GaAs | In order to further understand the pulsed-laser melting (PLM) of Mn and N implanted GaAs, which we have used to synthesize thin films of the ferromagnetic semiconductor Ga1−xMnxAs and the highly mismatched alloy GaNxAs1−x, we have simulated PLM of amorphous (a-) and crystalline (c-) GaAs. We pre... | | 2010 |
11 |
|
Scarpulla, Michael | Compositional tuning of ferromagnetism in Ga1-xMnxP | We report the magnetic and transport properties of Ga1-xMnxP synthesized via ion implantation followed by pulsed laser melting over a range of x, namely 0.018 to 0.042. Like Ga1-xMnxAs, Ga1-xMnxP displays a monotonic increase of the ferromagnetic Curie temperature with x associated with the hole-me... | Gallium arsenide; Ferromagnetic semiconductors | 2006-12 |
12 |
|
Scarpulla, Michael | Suppression of hole-mediated ferromagnetism in Ga1-xMnxP by hydrogen | We report the passivation of the Mn acceptors in Ga1−xMnxP upon exposure to a hydrogen plasma. The as-grown films are nonmetallic and ferromagnetic with a Curie temperature of TC=55 K. After hydrogenation the sample resistivity increases by approximately three orders of magnitude at room tempera... | Ferromagnetic semiconductors; Hydrogenation | 2008 |
13 |
|
Scarpulla, Michael | Compensation-dependent in-plane magnetization reversal processes in Ga1-xMnxP1-ySy | We report the effect of dilute alloying of the anion sublattice with S on the in-plane uniaxial magnetic anisotropy and magnetization reversal process in Ga1−xMnxP as measured by both ferromagnetic resonance (FMR) spectroscopy and superconducting quantum interference device (SQUID) magnetometry. ... | Ferromagnetic semiconductors; Nonmagnetic compensation | 2008-12 |
14 |
|
Scarpulla, Michael | Nonmagnetic compensation in ferromagnetic Ga1-xMnxAs and Ga1-xMnxP synthesized by ion implantation and pulsed-laser melting | The electronic and magnetic effects of intentional compensation with nonmagnetic donors are investigated in the ferromagnetic semiconductors Ga1−xMnxAs and Ga1−xMnxP synthesized using ion implantation and pulsed-laser melting. It is demonstrated that compensation with nonmagnetic donors and MnI ... | Ferromagnetic semiconductors | 2008 |
15 |
|
Scarpulla, Michael | Electrical transport and ferromagnetism in Ga1−xMnxAs synthesized by ion implantation and pulsed-laser melting | We present a detailed investigation of the magnetic and magnetotransport properties of thin films of ferromagnetic Ga1−xMnxAs synthesized using ion implantation and pulsed-laser melting (II-PLM). The field and temperature-dependent magnetization, magnetic anisotropy, temperature-dependent resist... | GaMnAs; Gallium arsenide | 2008 |
16 |
|
Scarpulla, Michael | Ga1-xMnxP synthesized by ion implantation and pulsed-laser melting | The synthesis of single-crystalline epitaxial thin films of the carrier-mediated ferromagnetic phase of Ga1-xMnxP and Ga1-xMnxP-based quaternary alloys using ion implantation and pulsed-laser melting (II-PLM) has allowed for the exploration of the effect of anion substitution on ferromagnetism in Ga... | | 2008 |
17 |
|
Scarpulla, Michael | Magnetocrystalline anisotropy and magnetization reversal in Ga1-xMnxP synthesized by ion implantation and pulsed-laser melting | We report the observation of ferromagnetic resonance (FMR) and the determination of the magnetocrystalline anisotropy in (100)-oriented single-crystalline thin film samples of Ga1−xMnxP with x=0.042. The contributions to the magnetic anisotropy were determined by measuring the angular and the te... | Magnetocrystalline anisotropy; GaMnAs; Gallium arsenide | 2007-06 |
18 |
|
Scarpulla, Michael | Pulsed and continuous wave solid phase laser annealing of electrodeposited CuInSe2 thin films | Cu(In,Ga)Se2 (CIGS) thin film photovoltaic absorber layers are primarily synthesized by vacuum based techniques at industrial scale. In this work, we investigate non-vacuum film synthesis by electrochemical deposition coupled with pulsed laser annealing (PLA) and or continuous wave laser annealing (... | | 2012-01-01 |