scholarly journals Role of electronegativity on the bulk modulus, magnetic moment and band gap of Co2MnAl based Heusler alloys

2019 ◽  
Vol 4 (1) ◽  
pp. 158-162
Author(s):  
Author-Shiv Om Kumar ◽  
Vineeta Shukla ◽  
Sanjeev Kumar Srivastava
Keyword(s):  
Bulk Modulus ◽  
Band Gap ◽  
Magnetic Moment ◽  
Heusler Alloys

scholarly journals Role of Bi3+ ions on structural, optical, photoluminescence and electrical performance of Cd0.9-xZn0.1BixS QDs

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
A. Krishnamoorthy ◽  
P. Sakthivel ◽  
I. Devadoss ◽  
V. M. Anitha Rajathi
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Optical Transmittance ◽  
Electrical Performance ◽  
Chemical Route ◽  
Red Emission ◽  
The Mean ◽  
Cubic Structure ◽  
Cyclic Voltammetry Analysis

AbstractIn this work, the Cd0.9-xZn0.1BixS QDs with different compositions of Bi3+ ions (0 ≤ x ≤ 0.05) were synthesized using a facile chemical route. The prepared QDs were characterized for analyzing the structural, morphological, elemental, optical, band gap, photoluminescence and electrochemical properties. XRD results confirmed that the Cd0.9-xZn0.1BixS QDs have a cubic structure. The mean crystallite size was increased from ~ 2 to ~ 5 nm for the increase of Bi3+ ions concentration. The optical transmittance behavior was decreased with increasing Bi3+ ions. The scanning electron microscope images showed that the prepared QDs possessed agglomerated morphology and the EDAX confirmed the presence of doped elements as per stoichiometry ratio. The optical band gap was slightly blue-shifted for initial substitution (Bi3+  = 1%) of Bi3+ ions and red-shifted for further increase of Bi3+ compositions. The optical band gap was ranged between 3.76 and 4.0 eV. High intense red emission was received for Bi3+ (1%) doped Zn:CdS QDs. The red emission peaks were shifted to a higher wavelength side due to the addition of Bi3+ ions. The PL emission on UV-region was raised for Bi3+ (1%) and it was diminished. Further, a violet (422 nm) and blue (460 nm) emission were received for Bi3+ ions doping. The cyclic voltammetry analysis showed that Bi3+ (0%) possessed better electrical properties than other compositions of Bi3+ ions.

scholarly journals The role of Ni-Mn hybridization on the martensitic phase transitions in Mn-rich Heusler alloys

2012 ◽  
Vol 100 (17) ◽  
pp. 172403 ◽  
Author(s):  
Mahmud Khan ◽  
J. Jung ◽  
S. S. Stoyko ◽  
Arthur Mar ◽  
Abdiel Quetz ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Heusler Alloys ◽  
Martensitic Phase ◽  
Martensitic Phase Transitions

Role of Surface Band Gap Widening in Cu(In, Ga)(Se, S)2 Thin-Films for the Photovoltaic Performance of ZnO/CdS/Cu(In, Ga)(Se, S)2 Heterojunction Solar Cells

2003 ◽  
Vol 763 ◽  
Author(s):  
U. Rau ◽  
M. Turcu
Keyword(s):  
Thin Films ◽  
Surface Layer ◽  
Solar Cells ◽  
Fermi Level ◽  
Band Gap ◽  
Photovoltaic Performance ◽  
Heterojunction Solar Cells ◽  
Fermi Level Pinning ◽  
Device Efficiency

AbstractNumerical simulations are used to investigate the role of the Cu-poor surface defect layer on Cu(In, Ga)Se2 thin-films for the photovoltaic performance of ZnO/CdS/Cu(In, Ga)Se2 heterojunction solar cells. We model the surface layer either as a material which is n-type doped, or as a material which is type-inverted due to Fermi-level pinning by donor-like defects at the interface with CdS. We further assume a band gap widening of this layer with respect to the Cu(In, Ga)Se2 bulk. This feature turns out to represent the key quality of the Cu(In, Ga)Se2 surface as it prevents recombination at the absorber/CdS buffer interface. Whether the type inversion results from n-type doping or from Fermi-level pinning is only of minor importance as long as the surface layer does not imply a too large number of excess defects in its bulk or at its interface with the normal absorber. With increasing number of those defects an n-type layer proofs to be less sensitive to material deterioration when compared to the type-inversion by Fermi-level pinning. For wide gap chalcopyrite solar cells the internal valence band offset between the surface layer and the chalcopyrite appears equally vital for the device efficiency. However, the unfavorable band-offsets of the ZnO/CdS/Cu(In, Ga)Se2 heterojunction limit the device efficiency because of the deterioration of the fill factor.

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