scholarly journals Optical properties of CuSe thin films - band gap determination

2017 ◽  
Vol 49 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Milica Petrovic ◽  
Martina Gilic ◽  
Jovana Cirkovic ◽  
Maja Romcevic ◽  
Nebojsa Romcevic ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Room Temperature ◽  
Nir Spectroscopy ◽  
Copper Selenide ◽  
Photoluminescence Spectra ◽  
Indirect Transition ◽  
Direct Transition ◽  
Scanning Electron

Copper selenide thin films of three different thicknesses have been prepared by vacuum evaporation method on a glass substrate at room temperature. The optical properties of the films were investigated by UV-VIS-NIR spectroscopy and photoluminescence spectroscopy. Surface morphology was investigated by field-emission scanning electron microscopy. Copper selenide exhibits both direct and indirect transitions. The band gap for direct transition is found to be ~2.7 eV and that for indirect transition it is ~1.70 eV. Photoluminescence spectra of copper selenide thin films have also been analyzed, which show emission peaks at 530, 550, and 760 nm. The latter corresponds to indirect transition in investigated material.

scholarly journals Low-temperature photoluminescence of CuSe2 nano-objects in selenium thin films

2017 ◽  
Vol 11 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Martina Gilic ◽  
Milica Petrovic ◽  
Jovana Cirkovic ◽  
Novica Paunovic ◽  
Svetlana Savic-Sevic ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Room Temperature ◽  
Band Gaps ◽  
Photoluminescence Spectra ◽  
Indirect Transition ◽  
Direct Transition ◽  
Direct Band Gap ◽  
Vis Spectroscopy ◽  
Direct Band

Thin films of CuSe2 nanoparticles embedded in selenium matrix were prepared by vacuum evaporation method on a glass substrate at room temperature. The optical properties of the films were investigated by photoluminescence spectroscopy (T=20-300K) and UV-VIS spectroscopy (T = 300K). Surface morphology was investigated by scanning electron microscopy. The band gap for direct transition in CuSe2 was found to be in the range of 2.72-2.75 eV and that for indirect transition is in the range of 1.71-1.75 eV determined by UV-VIS spectroscopy. On the other hand, selenium exhibits direct band gap in the range of 2.33-2.36 eV. All estimated band gaps slightly decrease with the increase of the film thickness. Photoluminescence spectra of the thin films clearly show emission bands at about 1.63 and 2.32 eV at room temperature, with no shift observed with decreasing temperature. A model was proposed for explaining such anomaly.

Composition Dependent Optical Properties of Zn1-xCdxS Nanostructures

2013 ◽  
Vol 669 ◽  
pp. 335-339
Author(s):  
Xue Yun Song ◽  
Xiu Xi Wang ◽  
Xiang Hua Zeng ◽  
Yong Zhang ◽  
Yi Pei Hu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Optical Properties ◽  
Band Gap ◽  
Mole Fraction ◽  
Room Temperature ◽  
Lattice Structure ◽  
Red Shift ◽  
Alloy Nanoparticles ◽  
Photoluminescence Spectra ◽  
Room Temperature Photoluminescence

Zn1-xCdxS alloy nanoparticles have been prepared via solvothermal approach. The effects of the mole fraction of Cd on the nanoparticles’ structure, size and photoluminescence spectra were investigated. It shows that with increase in mole fraction of Cd, the lattice structure of Zn1-xCdxS changes from cubic to hexagonal, and the size of these nanoparticles varied within 6-40nm. Room temperature photoluminescence measurements show an intense red shift from 518nm to 662nm. And the band gap energies from 2.3 to 3.54eV can be realized for the Zn1-xCdxS nanopartices. Furthermore, it is found that the conversion of Methylene Blue (MB) using Zn0.6Cd0.4S as the photocatalyst was up to 97% after 2h of irradiation.

scholarly journals Investigation the effect of annealing temperature on the optical properties of CdSe thin films

2018 ◽  
Vol 6 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Sabah M. Ahmed ◽  
Raghad Y. Mohammed ◽  
Sedki O. Yousif
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Transmittance Spectrum ◽  
Stable Phase ◽  
Cdse Thin Film ◽  
Deposited Films

Introduction: CdSe is an important II–VI semiconducting material due to its typical optical properties such as small direct band gap (1.7 eV) and a high refractive index and, thus, a major concern is focused on the investigation of optical properties of CdSe thin films which is important to promote the performances of the devices of solid -state such as SC (solar cells), thin film transistors, LED (light-emitting diodes), EBPL (electron–beam pumped lasers) and electroluminescent devices. In the present work, CdSe thin films were deposited by thermal evaporation method and the results have been analysed and presented. Materials and Methods: CdSe thin films has been deposited on glass microscopic slides as substrates of (75×25×1 mm) under room temperature using PVD technique. CdSe blended powders gets evaporated and condensed on the substrate. The film thickness (t = 100 ± 5 nm) which is measured using Michelson interferometry method. Transmission spectrum, from 200-1100 nm, are scanned using two beams UV–VIS Spectrophotometer (6850 UV/Vis. Spectrophotometer-JENWAY). The deposited films then were annealed at temperature range of (1500C to 3500C) under vacuum to have a stable phase of the material and prevent surface oxidization. Results and Discussion: A transmittance spectrum of CdSe thin film is scanned over wavelength range 200 to 1100 nm using a (6850 UV/Vis. Spectrophotometer-JENWAY) at room temperature. The transmittance percentage between the as-deposited film and the annealed films change varies from (17.0%) to (47.0%). It is clearly seen that there is a shift toward higher energy (Blue Shift) in the transmittance spectrum. As annealing temperature increased the transmittance edge is shifted to the longer wavelength (i.e., after annealing the CdSe films shows red shifts in their optical spectra). The band gap was found within the range 1.966-1.7536 eV for CdSe thin film. As annealing temperature increases, the Eg continuously decreases. Conclusions: CdSe thin films have been deposited using Physical Vapor Deposition (PVD) Technique. It is found that the transmission for as- deposited films is (17%) and increases to (47%) as annealing temperature increases. Beside this the energy gap for as- deposited CdSe film is (1.966eV) and decreased from (1.909 eV) to (1.7536eV) as the annealing temperature increases. There is a strong red shift in the optical spectrum of the annealed CdSe films. There is a gradual shift of the annealed films thin film spectra as compared of bulk CdSe films.

Effects of Different Thermal Treatment on Optical Properties and Microstructure of ZnO Thin Films

2011 ◽  
Vol 197-198 ◽  
pp. 1766-1770 ◽  
Author(s):  
Dong Ping Zhang ◽  
Ping Fan ◽  
Zhuang Hao Zheng ◽  
Li Li Ru ◽  
Jian Jun Huang ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Constant Temperature ◽  
Room Temperature ◽  
Optical Band Gap ◽  
The Other ◽  
Zno Thin Films ◽  
Zno Films ◽  
Dc Reactive Magnetron Sputtering

ZnO thin films were prepared by DC reactive magnetron sputtering at room temperature. Two of them were annealed with different modes under vacuum condition. One was annealed with constant temperature of 300°C ; the other was annealed with temperature rising step by step from room temperature to 300°C . By comparing the microstructure and optical properties of the as-grown and annealed samples, the effects of different annealing modes on ZnO films performances were revealed. The experiment results investigated that the sample annealed with constant temperature of 300°C has the high grain size and surface roughness. Both of the two annealing modes could release the intrinsic stresses to some degree. The optical band gap of the samples narrowed after annealing, and the two annealed samples have almost the same band gap. Strong green emissions are observed for all the samples, but the emission intensity decreased of the sample annealed with the temperature rising step by step compared with that of other samples.

scholarly journals Optical Properties of Al- and Sb-Doped CdTe Thin Films

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
A. A. J. Al-Douri ◽  
F. Y. Al-Shakily ◽  
M. F. A. Alias ◽  
A. A. Alnajjar
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Room Temperature ◽  
Optical Transition ◽  
Coefficient Increase ◽  
Evaporation Technique ◽  
Direct Optical Transition ◽  
Cdte Thin Films ◽  
Substrate Temperatures

Nondoped and (Al, Sb)-doped CdTe thin films with 0.5, 1.5, and 2.5  wt.%, respectively, were deposited by thermal evaporation technique under vacuum onto Corning 7059 glass at substrate temperatures () of room temperature (RT) and 423 K. The optical properties of deposited CdTe films such as band gap, refractive index (n), extinction coefficient (), and dielectric coefficients were investigated as function of Al and Sb wt.% doping, respectively. The results showed that films have direct optical transition. Increasing and the wt.% of both types of dopant, the band gap decrease but the optical is constant asn, and real and imaginary parts of the dielectric coefficient increase.

Deposition time dependent study of structural and optical properties of PbS thin films grown by CBD method

2020 ◽  
Vol 13 ◽  
Author(s):  
Minakshi Chaudhary ◽  
Yogesh Hase ◽  
Ashwini Punde ◽  
Pratibha Shinde ◽  
Ashish Waghmare ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Deposition Time ◽  
Secondary Growth ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Structural Morphology ◽  
Glass Substrates ◽  
Cbd Method

: Thin films of PbS were prepared onto glass substrates by using a simple and cost effective CBD method. Influence of deposition time on structural, morphology and optical properties have been investigated systematically. The XRD analysis revealed that PbS films are polycrystalline with preferred orientation in (200) direction. Enhancement in crystallinity and PbS crystallite size has been observed with increase in deposition time. Formation of single phase PbS thin films has been further confirmed by Raman spectroscopy. The surface morphology analysis revealed the formation of prismatic and pebble-like PbS particles and with increase in deposition time these PbS particles are separated from each other without secondary growth. The data obtained from the EDX spectra shows the formation of high-quality but slightly sulfur rich PbS thin films over the entire range of deposition time studied. All films show increase in absorption with increase in deposition time and a strong absorption in the visible and sub-band gap regime of NIR range of the spectrum with red shift in band edge. The optical band gap shows decreasing trend, as deposition time increases but it is higher than the band gap of bulk PbS.

Electrical and Optical Properties of Si+ and P+ Implanted InP:Fe

1990 ◽  
Vol 201 ◽  
Author(s):  
Honglie Shen ◽  
Genqing Yang ◽  
Zuyao Zhou ◽  
Guanqun Xia ◽  
Shichang Zou
Keyword(s):  
Optical Properties ◽  
Silicon Nitride ◽  
Temperature Dependence ◽  
Optimal Condition ◽  
Room Temperature ◽  
Broad Band ◽  
Photoluminescence Spectra ◽  
Electrical And Optical Properties ◽  
Spectrum Measurement ◽  
Single Implant

AbstractDual implantations of Si+ and P+ into InP:Fe were performed both at 200°C and room temperature. Si+ ions were implanted by 150keV with doses ranging from 5×1013 /cm2 to 1×1015 /cm2, while P+ ions were implanted by 110keV. 160keV and 180keV with doses ranging from 1×l013 /cm2 to 1×1015 /cm2. Hall measurements and photoluminescence spectra were used to characterize the silicon nitride encapsulated annealed samples. It was found that enhanced activation can be obtained by Si+ and P+ dual implantations. The optimal condition for dual implantations is that the atomic distribution of implanted P overlaps that of implanted si with the same implant dose. For a dose of 5×l014 /cm2, the highest activation for dual implants is 70% while the activation for single implant is 40% after annealing at 750°C for 15 minutes. PL spectrum measurement was carried out at temperatures from 11K to 100K. A broad band at about 1.26eV was found in Si+ implanted samples, of which the intensity increased with increasing of the Si dose and decreased with increasing of the co-implant P+ dose. The temperature dependence of the broad band showed that it is a complex (Vp-Sip) related band. All these results indicate that silicon is an amphoteric species in InP.

Sol–gel synthesis and optical properties of titanium dioxide thin film

2018 ◽  
Vol 32 (09) ◽  
pp. 1850076 ◽  
Author(s):  
Irfan Ullah ◽  
Shaukat Ali Khattak ◽  
Tanveer Ahmad ◽  
Saman ◽  
Nayab Ali Ludhi
Keyword(s):  
Thin Film ◽  
Titanium Dioxide ◽  
Optical Properties ◽  
Band Gap ◽  
Surface Defects ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Localized States ◽  
Indirect Transition ◽  
Transmission And Absorption

The titanium dioxide (TiO2) is synthesized by sol–gel method using titanium-tetra-iso-propoxide (TTIP) as a starting material, and deposited on the pre-cleaned glass substrate using spin coating technique at optimized parameters. Energy dispersive X-ray (EDX) spectroscopy confirms successful TiO2 growth. The optical properties concerning the transmission and absorption spectra show 85% transparency and 3.28 eV wide optical band gap for indirect transition, calculated from absorbance. The exponential behavior of absorption edge is observed and attributed to the localized states electronic transitions, curtailed in the indirect band gap of the thin film. The film reveals decreasing refractive index with increasing wavelength. The photoluminescence (PL) study ascertains that luminescent properties are due to the surface defects.

Influence of Substrate Temperature on Structural and Optical Properties of Co-Evaporated Cu2SnS3/ITO Thin Films

2022 ◽  
Vol 1048 ◽  
pp. 189-197
Author(s):  
Tippasani Srinivasa Reddy ◽  
M.C. Santhosh Kumar
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Substrate Temperature ◽  
Indium Tin Oxide ◽  
Nir Spectroscopy ◽  
Stoichiometric Ratio ◽  
Tin Sulfide ◽  
Structural And Optical Properties ◽  
Average Grain Size ◽  
Deposited Films

In this study report the structural and optical properties of Copper Tin Sulfide (Cu2SnS3) thin films on indium tin oxide (ITO) substrate using co-evaporation technique. High purity of copper, tin and sulfur were taken as source materials to deposit Cu2SnS3 (CTS) thin films at different substrate temperatures (200-350 °C). Further, the effect of different substrate temperature on the crystallographic, morphological and optical properties of CTS thin films was investigated. The deposited CTS thin films shows tetragonal phase with preferential orientation along (112) plane confirmed by X-ray diffraction. Micro-Raman studies reveled the formation of CTS thin films. The surface morphology, average grain size and rms values of the deposited films are examined by Scanning electron spectroscopy (SEM) and Atomic Force Microscopy (AFM). The Energy dispersive spectroscopy (EDS) shows the presence of copper, tin and sulfur with a nearly stoichiometric ratio. The optical band gap (1.76-1.63 eV) and absorption coefficient (~105 cm-1) of the films was calculated by using UV-Vis-NIR spectroscopy. The values of refractive index, extinction coefficient and permittivity of the deposited films were calculated from the optical transmittance data.

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