ACTIVATION ENERGIES OF SEMICONDUCTORS WITH THE ZINC BLENDE STRUCTURE

1959 ◽  
Vol 37 (7) ◽  
pp. 1191-1196 ◽  
Author(s):  
W. B. Pearson
Keyword(s):  
Energy Gap ◽  
Activation Energies ◽  
Binding Energies ◽  
Zinc Blende ◽  
Effective Charges ◽  
Zinc Blende Structure ◽  
Systematic Explanation ◽  
Atomic Parameters

Difficulties of determining the binding energies and effective charges on the atoms are the main reason why no systematic explanation of the variation of the size of the energy gap among members of the simplest family of semiconductors—those with the zinc blende structure—has ever been given. It is shown that by the choice of suitable atomic parameters for discussing the activation energies of these compounds these difficulties may be avoided, and the variation of the size of the energy gap between one compound and another can be systematically accounted for. In the treatment which develops no particular distinction need be made between the III–V, II–VI, and I–VII compounds, and it is concluded that the anomalously high or low activation energies, which certain compounds appear to have, are just the result of the relative sizes of the cations and anions in influencing the polarization of the bonds.

A Study of the Photoluminescence and Reflectivity Spectra of MOCVD Grown MnSe

1994 ◽  
Vol 340 ◽  
Author(s):  
M. Di Blasio ◽  
L. Aigouy ◽  
M. Averous ◽  
J. Calas ◽  
P. Tomasini ◽  
...  
Keyword(s):  
Energy Gap ◽  
Stokes Shift ◽  
Thin Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zinc Blende ◽  
Reflectivity Spectra ◽  
Different Temperatures ◽  
First Time ◽  
Zinc Blende Structure

Photoluminescence (PL) experiments at 2K are performed on MOCVD grown MnSe. The precursors used in the growth stage are methylpentacarbonylmanganese and diethylselenide. Pyrolysis of the percursors is realized inside a gradient reactor under a constant H2 flux, between 280-55°TC. The compound is epitaxially grown on various substrates (Si, InP, GaSb, GaAs, ZnTe/GaAs, etc.). On some of these samples the compound presents a zinc blende structure, while in the other samples rock salt formation has been identified. The first substrate is used because of its interest in Si technology, while the others are used because MnSe can be grown in the zinc blende phase for very thin layers. For the first time x-ray diffraction data has allowed us to determine the lattice constant of zincblende MnSe (aMnse (oct)=5.818Å), confirming the close approximation (a ∼ 5.9Å) used from the Zn1-xMnxSe alloy. These compounds have visible Mn++ transitions at 2.12-5eV; other features are also visible at 2.3-4, 2.7, and 3.0eV. The energy gap transition of tetrahedral thin film layers of MnSe is seen for the first time in PL spectra. A temperature dependant PL study is performed on MnSe in the 2-200K range. Reflectivity experiments are used to attempt to identify the internal manganese transitions. A qualitative PL analysis of the samples grown at different temperatures and on different substrates is provided. A Stokes shift is encountered when the results are compared.

Structural and Optical Properties of ZnS:Mn Films Grown by Pulsed Laser Deposition

2001 ◽  
Vol 667 ◽  
Author(s):  
K. M. Yeung ◽  
S. G. Lu ◽  
C. L. Mak ◽  
K. H. Wong
Keyword(s):  
Optical Properties ◽  
Substrate Temperature ◽  
Pulsed Laser Deposition ◽  
Energy Gap ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Yellow Emission ◽  
Wurtzite Phase ◽  
Zinc Blende ◽  
Zinc Blende Structure

ABSTRACTHigh-quality manganese-doped zinc sulfide (ZnS:Mn) thin films have been deposited on various substrates using pulsed laser deposition (PLD). Effects of back-filled Ar pressure and substrate temperature on the structural as well as optical properties of ZnS:Mn films were studied. Structural properties of these films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Photoluminescence (PL) and optical transmittance were used to characterize the optical properties of these films. Our results reveal that ZnS:Mn films were polycrystalline with a mixed phase structure consisting of both wurtzite and zinc-blende structure. The ratio of these two structures was strongly depended on the change of substrate temperature. Low substrate temperature facilitated the formation of zinc-blende structure while the wurtzite phase became dominant at high substrate temperature. ZnS:Mn films with preferred wurtzite structure were obtained at a substrate temperature as low as 450°C. An orange-yellow emission band was observed at ∼590 nm. As the substrate temperature increased, the peak of this PL band shifted to a shorter wavelength. Furthermore, shifts in the absorption edge and the energy gap due to the change in substrate temperature were also observed. The variation in these optical properties will be correlated to their structural change.

COMPOSITION DEPENDENCE OF THE POSITRON ANNIHILATION IN Zn1-xBexSe

2005 ◽  
Vol 19 (17) ◽  
pp. 849-860
Author(s):  
F. BENKABOU
Keyword(s):  
Positron Annihilation ◽  
Energy Gap ◽  
Momentum Density ◽  
Annihilation Radiation ◽  
Virtual Crystal Approximation ◽  
Zinc Blende ◽  
Electron Positron ◽  
Wide Energy ◽  
Pseudo Potential ◽  
Zinc Blende Structure

In order to clarify the electronic and optical properties of wide-energy gap zinc-blende structure ZnSe , BeSe and their alloys, a simple pseudo-potential scheme (EPM), within an affective potential the virtual crystal approximation (VCA) which incorporates compositional disorder as an effective potential are presented. Angular correlation of positron annihilation radiation (ACPAR) along different crystallographic directions in Zn 1-x Be x Se are calculated. We observe that the electron-positron momentum density increases rapidly with increasing Beryllium content.

Sputter Deposition of Fe-Co Nitride for Ferromagnetic Granular Nitride Thin Film

2009 ◽  
Vol 631-632 ◽  
pp. 327-331 ◽  
Author(s):  
K. Sakon ◽  
Y. Hirokawa ◽  
Yasuji Masubuchi ◽  
Shinichi Kikkawa
Keyword(s):  
Thin Film ◽  
Solid Solution ◽  
Thermal Decomposition ◽  
Sputter Deposition ◽  
Composite Target ◽  
Zinc Blende ◽  
Alloy Particles ◽  
Sputter Deposited ◽  
Magneto Resistance ◽  
Zinc Blende Structure

Sputter deposited Fe0.7Co0.3 nitride thin film had zinc blende structure. It was thermally decomposed completely back to the ferromagnetic Fe0.7Co0.3 alloy above 400°C. As-deposited nitride thin films obtained in cosputtering of (Fe0.7Co0.3)1-xAlx composite target with nitrogen sputter gas were solid solutions with zinc blende (x≤0.44) and wurtzite (x>0.5) type structure, respectively. The largest magneto resistance ratio of 0.24% was observed on the Fe0.7Co0.3 alloy particles dispersed in AlN thin film obtained by thermal decomposition of the nitride solid solution with x=0.66 at 500°C.

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