Near‐band gap optical behavior of sputter deposited α‐ and α+β‐ZrO2films

1989 ◽  
Vol 66 (6) ◽  
pp. 2756-2758 ◽  
Author(s):  
Chee‐Kin Kwok ◽  
Carolyn Rubin Aita
Keyword(s):  
Band Gap ◽  
Sputter Deposited ◽  
Optical Behavior

Optical Absorption of Erbium Doped Tellurite Glass

2014 ◽  
Vol 895 ◽  
pp. 245-249 ◽  
Author(s):  
Siti Ismail Fatimah ◽  
Md Rahim Sahar ◽  
Sib Krishna Ghoshal ◽  
R. Arifin ◽  
K. Hamzah
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Tellurite Glass ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Rare Earth Doping ◽  
X Ray Diffraction ◽  
Indirect Transition ◽  
Erbium Doped ◽  
Optical Behavior

Improving the optical behavior of tellurite glass with controlled rare earth doping is an important issue from device perspectives. The Er3+ -doped tellurite glasses having composition (75-x)TeO2-20ZnO-5Na2O-xEr2O3 where (0 x 0.7) mol% are prepared by melt quenching technique and their structural and optical properties are investigated. Amorphous nature of the samples is confirmed through X-ray diffraction technique. The optical absorption recorded at room temperature in the wavelength range from 400 to 1000 nm exhibits five broad bands. The value of the optical band gap and the Urbach energy (ΔE) are calculated from the absorption edge data. The value of optical band gap lies between 2.18 eV and 2.89 eV for the indirect transition whereas the value of Urbach energy varies from 0.15 to 0.53 eV. The optical band gap and Urbach energy values are found to dependent strongly on the erbium concentration.

scholarly journals Effect of Nickel Doping on Optical Properties of CdS Nanoparticles Synthesized via. Co-precipitation Technique

2017 ◽  
Vol 14 (1) ◽  
pp. 05-08 ◽  
Author(s):  
Suresh Kumar ◽  
J. K Sharma
Keyword(s):  
Band Gap ◽  
Cadmium Sulphide ◽  
Cds Nanoparticles ◽  
Nickel Doping ◽  
Quantum Size ◽  
Precipitation Technique ◽  
Uv Visible ◽  
Co Precipitation ◽  
Optical Behavior ◽  
Comprehensive Study

This work presents a comprehensive study on the optical behavior of cadmium sulphide (CdS) nanoparticles under the effect of nickel (Ni2+ ions) doping. The pristine and Ni-doped CdS nanoparticles (CdS:Ni) have been synthesized via. conventional co-precipitation technique and analyzed using UV-visible spectrophotometer. Ni2+ ions with different concentrations (2% and 4%) incorporate in CdS structure, modify it and hence, exhibit a red shift of absorption edge. The increase in Ni2+ ions concentration from 0% to 4% leads to tailor the optical band gap of CdS from 2.70 eV to 2.47 eV. These band gap values are higher than that of bulk CdS which confirm a quantum size effect in the synthesized nanoparticles.

scholarly journals Band Gap Characterization of Thermally Treated Hybrid Blend ZnPc/CdS Thin Films

2019 ◽  
Vol 17 (43) ◽  
pp. 94-102
Author(s):  
Holya A. Alobaidy
Keyword(s):  
Thin Films ◽  
Absorption Spectrum ◽  
Band Gap ◽  
Annealing Time ◽  
Spin Coating ◽  
Energy Gap ◽  
Conductivity Measurement ◽  
Cds Thin Films ◽  
Optical Behavior

Spin coating technique used to prepare ZnPc, CdS and ZnPc/CdS blend thin films, these films annealed at 423K for 1h, 2h and 3h. Optical behavior of these films were examined using UV-Vis. and PL. The absorption spectrum of ZnPc shows a decreasing in absorption with the increase of annealing time while CdS spectrum give a clearly absorption peak at~510 nm. Energy gap of ZnPc increases from 1.41 to 1.52 eV by increasing the annealing time. Eg of CdS decrease by increasing annealing time, from 2.3 eV to 2.2 eV. The intensities of the peaks obtained from PL spectra were strongly dependent on annealing time and confirmed the results obtained from UV-Vis. D.C. conductivity measurement showed that all the thin films have two different activation energies in the temperature range 303–473K.

Band-gap engineering in sputter-deposited ScxGa1−xN

2001 ◽  
Vol 78 (19) ◽  
pp. 2891-2892 ◽  
Author(s):  
M. E. Little ◽  
M. E. Kordesch
Keyword(s):  
Band Gap ◽  
Band Gap Engineering ◽  
Sputter Deposited

Phase Mapping Sputter Deposited Wide Band-Gap Metal Oxides

1992 ◽  
Vol 242 ◽  
Author(s):  
C.R. Aita ◽  
R.C. Lee ◽  
C.-K. Kwok ◽  
E.A. Kolawa
Keyword(s):  
Metal Oxides ◽  
Band Gap ◽  
Wide Band ◽  
Oxide Phase ◽  
Deposition Process ◽  
Sputter Deposition ◽  
Wide Band Gap ◽  
Growth Environment ◽  
Reactive Sputter Deposition ◽  
Sputter Deposited

ABSTRACTReactive sputter deposition is a widely-used process for growing films of high melting point materials near room temperature and desirable metastable structures not attainable in material grown under conditions of thermodynamic equilibrium. Both categories include wide band-gap metal oxides. A first step towards reproducible growth is to develop a “phase map” for the metal-oxygen system of interest. The map graphically relates independent sputter deposition process parameters, the growth environment, and the metallurgical phase(s) formed in the film. This paper shows how phase maps are constructed and used to observe general trends in oxide phase formation sequence, with examples from the Nb-O, Y-O, and Zr-O systems.

Optical Behavior of Sputter-Deposited Aluminum Nitride: Relationship to Film Cheiistry

1985 ◽  
Vol 47 ◽  
Author(s):  
C. J. G. Kubiak ◽  
C. R. Aita ◽  
F. S. Hickernell ◽  
S. J. Joseph
Keyword(s):  
Aluminum Nitride ◽  
Sputter Deposition ◽  
Aluminum Target ◽  
Reactive Sputter Deposition ◽  
Sputter Deposited ◽  
Excited Nitrogen ◽  
Amorphous Quartz ◽  
Quartz Substrates ◽  
Optical Behavior

ABSTRACTFilms which are nominally aluminum nitride were grown by reactive sputter deposition using an aluminum target and rf-excited nitrogen discharges operated at power levels from 100 to 800W. Depositions were made on water-cooled (111)-cut Si and amorphous quartz substrates. The optical behavior of these films and its relationship to chemistry is discussed in the present paper.

Thin Film WSe2 for Use as a Photovoltaic Absorber Material

2014 ◽  
Vol 1670 ◽  
Author(s):  
Qinglei Ma ◽  
Hrachya Kyureghian ◽  
Joel D. Banninga ◽  
N. J. Ianno
Keyword(s):  
Thin Film ◽  
Band Gap ◽  
Optical Band Gap ◽  
Visible Spectrum ◽  
Absorber Material ◽  
Excellent Candidate ◽  
Earth Abundant ◽  
Type Semiconductor ◽  
Sputter Deposited ◽  
P Type

ABSTRACTAn excellent candidate for an earth abundant absorber material is WSe2 which can be directly grown as a p-type semiconductor with a band gap near 1.4 eV. In this work we present the structural, optical, and electrical properties of thin film WSe2 grown via the selenization of sputter deposited tungsten films. We will show that highly textured films with an optical band gap in range of 1.4 eV, and absorption coefficients greater than 105/cm across the visible spectrum can be easily achieved. In addition we will present Hall Effect and carrier density measurements as well, where will show densities in the 1017cm-3 range and p-type Hall mobilities greater than 10 cm2/V-s range can be obtained. We employ these results to numerically simulate solar cells based on this material, where we will show efficiencies greater than 20% are possible.

Dielectric Tensor Characterization for Overcoated Amorphous TbFe Alloys

1986 ◽  
Vol 80 ◽  
Author(s):  
M. Ruane ◽  
A. Jain ◽  
R. Rosenvold ◽  
M. Mansuripur
Keyword(s):  
Protective Layer ◽  
Estimation Algorithm ◽  
Optical Signal ◽  
Dielectric Tensor ◽  
Amorphous Thin Films ◽  
Sputter Deposited ◽  
Reflectivity Data ◽  
Quartz Substrates ◽  
Optical Behavior ◽  
Made In

AbstractAmorphous thin films of TbFe. sputter-deposited on quartz substrates with compositions supporting polar Kerr magneto-optical behavior, and overcoated with a transparent protective layer, are studied to determine their dielectric tensor elements. Refleetivity measurements over a range of angles of incidence are made in an apparatus that corrects for the overcoat layer and exploits magnetization reversal to enhance the measurement of r⊥, the complex reflectivity associated with the magneto-optical signal. Conventional Fresnel reflectivities are also found. The theoretical model for reflectivities from a thick film magneto-optical medium at oblique incidenci is developed and used within a Levenberg-Marquardt nonlinear estimation algorithm to estimate sequentially the dielectric tensor elements, considering their widely varying magnitudes and sensitivities to errors in reflectivity data. The interpretation of the dielectric elements in terms of magneto-optical performance and structural perpendicular anisotropy is discussed.

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