scholarly journals Some New Nickel 1,2-Dichalcogenolene Complexes as Single-component Semiconductors

2007 ◽  
Vol 62 (5) ◽  
pp. 679-684 ◽  
Author(s):  
George C. Papavassiliou ◽  
George C. Anyfantis ◽  
Barry R. Steele ◽  
Barry R. Steele ◽  
Aris Terzis ◽  
...  
Keyword(s):  
Band Gap ◽  
Single Component ◽  
Semiconducting Behavior ◽  
Gap Values

Abstract The complexes Ni(dmeds)(dmit), Ni(dmedt)(dmit), Ni(dpedt)(dsit), Ni(dpedt)(dmit), and Ni(dcdt)(dmit) (where dmeds is dimethylethylenediselenolate, dmedt is dimethylethylenedithiolate, dpedt is diphenylethylenedithiolate, dcdt is 1,2-bis-decylsulfanyl-ethene-1,2-dithiolate, dmit is 1,3-dithiol-2-thione-4,5-dithiolate, and dsit is 1,3-dithiol-2-thione-4,5-diselenolate) were prepared and characterized. The new complexes exhibit semiconducting behavior, with band gap values around 0.8 eV.

Photoconductivity of monocrystals of CdIn2S4

1984 ◽  
Vol 62 (9) ◽  
pp. 883-888 ◽  
Author(s):  
A. B. Vincent ◽  
C. E. Rodríguez ◽  
N. V. Joshi
Keyword(s):  
Band Gap ◽  
High Photosensitivity ◽  
Gap Values

Photoconductivity spectra of monocrystals of CdIn2S4, some of which were annealed in a sulphur-rich atmosphere, have been studied in order to understand the origin of the high photosensitivity. It is found that sulphur enriched CdIn2S4 shows a high photoresponse. The data presented explain observed discrepancies in the band gap values. An origin for the slow photoresponse is also examined.

Determination of band gap in polycrystalline Si/Ge thin film multilayers

2006 ◽  
Vol 21 (3) ◽  
pp. 623-631 ◽  
Author(s):  
S. Tripathi ◽  
R. Brajpuriya ◽  
C. Mukharjee ◽  
S.M. Chaudhari
Keyword(s):  
Thin Film ◽  
Particle Size ◽  
Band Gap ◽  
Quantum Confinement ◽  
Near Infrared ◽  
Quantum Confinement Effect ◽  
Multilayer Structures ◽  
Absorption Measurements ◽  
Gap Values

The valence band (VB) photoemission supported by ultraviolet–visible–near infrared spectroscopy techniques were used to determine the band gap values of polycrystalline Si and Ge single layers as well as of Si/Ge multilayer structures. The band gap values obtained from VB photoemission measurements for these structures were found to be much larger than their corresponding bulks and to match well with those determined from standard optical absorption measurements. In each case, the VB offset values were obtained by considering the corresponding VB maximum as a reference. The increase in band gap in case of thin single layers of Si and Ge with respect to bulks were interpreted in terms of quantum confinement effect, while in case of multilayer sample, the effect of various factors such as (i) intermixing leading to the formation of SiGe alloy, (ii) roughness at the interface, (iii) particle size, and (iv) strain seem to play an important role in the observed change in band gap.

Semiconducting behavior of Ag2Te thin films and the dependence of band gap on thickness

1983 ◽  
Vol 54 (9) ◽  
pp. 5252-5255 ◽  
Author(s):  
V. Damodara Das ◽  
D. Karunakaran
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Semiconducting Behavior

BAND GAP PREDICTION OF ALLOYED SEMICONDUCTORS

2011 ◽  
Vol 04 (03) ◽  
pp. 217-219 ◽  
Author(s):  
KEYAN LI ◽  
YANJU LI ◽  
DONGFENG XUE
Keyword(s):  
Experimental Data ◽  
Band Gap ◽  
Efficient Method ◽  
Dopant Concentration ◽  
Band Gap Engineering ◽  
Gap Values

We have proposed an efficient method to quantitatively calculate the band gap values of ternary A x B 1-x C and AB x C 1-x alloyed semiconductors in terms of the dopant concentration x and some fundamental atom parameters such as electronegativity. The calculated band gap values of some typical alloyed semiconductors can agree well with the available experimental data. Taking Mg x Zn 1-x O and Cd x Zn 1-x O as examples, the composition dependent band gap values of alloys with both wurtzite and rocksalt structures were quantitatively predicted. This work provides a guideline in compositionally tuning the band gap of alloyed semiconductors, which will greatly facilitate the band gap engineering of semiconductors.

Optical applications of transition metal ion doped phosphate glasses

2021 ◽  
Author(s):  
Modem Sreenivasulu ◽  
Vijaya Kumar Chavan
Keyword(s):  
Transition Metal ◽  
Band Gap ◽  
Energy Band ◽  
Metal Ion ◽  
Phosphate Glasses ◽  
Transmission Spectra ◽  
Energy Band Gap ◽  
Transition Metal Ion ◽  
Concentration Levels ◽  
Gap Values

Abstract The transition metal ion-doped lithium phosphate glasses are prepared with a novel composition by melt quenching method, XRD patterns revealed their characteristic amorphous nature. The structural and physical properties of the prepared glasses are significantly varying with the increased concentration levels of dopant. Optical absorption and transmission spectra of the glass samples are analyzed. The absorption peaks are observed in ultraviolet, visible and infrared regions.The direct and indirect energy band gap values are decreasing while Urbach's energy values are increasing as the concentration levels of dopants are increasing. The obtained energy band gap values are in the range of semiconductor materials. The optical transmission spectra of these transition metal ion-doped glasses reveal their application as bandpass filters with filtering ability in UV or Visible regions at double and triple wavelengths and hence useful as dual band-pass filters. The glasses with <10 full width half maximum(FWHM) values are useful for narrowband lasers.

scholarly journals Estimation of Lattice Constants and Band Gaps of Group-III Nitrides using Local and Semi Local Functionals

2018 ◽  
Vol 34 (4) ◽  
pp. 2137-2143 ◽  
Author(s):  
Sandeep Arora ◽  
Dharamvir Singh Ahlawat ◽  
Dharambir Singh
Keyword(s):  
Band Gap ◽  
Local Density ◽  
Group Iii Nitrides ◽  
Lattice Parameters ◽  
Exchange Potential ◽  
Generalized Gradient ◽  
Group Iii ◽  
Lattice Constants ◽  
Mean Error ◽  
Gap Values

We performed the optimization of lattice constants of Group- III nitrides (InN, AlN, GaN) in wurtzite and Zinc blende structures using various semilocal exchange correlation functional in generalized gradient approximations (GGA) namely PBE, WC, PBEsol in addition to local density approximation (LDA) functional. We used these optimized lattice parameters to predict the band gap values using modified Becke Johnson exchange potential with original and improved parameterization as suggested by David Koller for semiconductors having band gap values below 7eV. Among the different functionals considered, PBEsol optimize the lattice parameters with smallest mean error (0.00639 Å) relative to experimental values, while WC approximation with a slightly greater value of mean error (0.00513 Å). It is shown that mBJLDA approximation improves the band gap for the materials studied when compared with LDA and GGA results. It is also shown that LDA optimized parameters with mBJLDA approximation, which leads to mean error of 0.162 eV reproduces the experimental band gap in most efficient way.

Co2+ and Ho3+ doped CuS nanocrystals with improved photocatalytic activity under visible light irradiation

RSC Advances ◽  
2016 ◽  
Vol 6 (48) ◽  
pp. 42581-42588 ◽  
Author(s):  
Zahra Hosseinpour ◽  
Sara Hosseinpour ◽  
Malik Maaza ◽  
Alice Scarpellini
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Hydrothermal Method ◽  
Visible Light Irradiation ◽  
Photocatalytic Performance ◽  
Light Irradiation ◽  
Gap Values

Co2+ and Ho3+ doped CuS nanostructures have been synthesized by a hydrothermal method. The nature of dopants influence the morphology, photocatalytic performance and the band gap values.

Tuning Electronic and Structural Properties of Triple Layers of Intercalated Graphene and Hexagonal Boron Nitride: An Ab-initio Study.

2011 ◽  
Vol 1307 ◽  
Author(s):  
Samir S. Coutinho ◽  
David L. Azevedo ◽  
Douglas S. Galvão
Keyword(s):  
Boron Nitride ◽  
Electric Field ◽  
Ab Initio ◽  
Band Gap ◽  
External Electric Field ◽  
Structural Properties ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Electronic And Structural Properties ◽  
Gap Values

ABSTRACTRecently, several experiments and theoretical studies demonstrated the possibility of tuning or modulating band gap values of nanostructures composed of bi-layer graphene, bi-layer hexagonal boron-nitride (BN) and hetero-layer combinations. These triple layers systems present several possibilities of stacking. In this work we report an ab initio (within the formalism of density functional theory (DFT)) study of structural and electronic properties of some of these stacked configurations. We observe that an applied external electric field can alter the electronic and structural properties of these systems. With the same value of the applied electric field the band gap values can be increased or decreased, depending on the layer stacking sequences. Strong geometrical deformations were observed. These results show that the application of an external electric field perpendicular to the stacked layers can effectively be used to modulate their inter-layer distances and/or their band gap values.

scholarly journals Evidence for semiconducting behavior with a narrow band gap of Bernal graphite

2012 ◽  
Vol 14 (5) ◽  
pp. 053015 ◽  
Author(s):  
N García ◽  
P Esquinazi ◽  
J Barzola-Quiquia ◽  
S Dusari
Keyword(s):  
Band Gap ◽  
Narrow Band ◽  
Semiconducting Behavior
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