Formation of a-Si:H Film by p-CVD Method with SiH4-He Mixture and its Opto-Electronic Properties

1995 ◽  
Vol 377 ◽  
Author(s):  
Youichi Nakamura ◽  
Tsuyoshi Yamaguchi ◽  
Atsushi Okagawa
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Optical Band Gap ◽  
Emission Spectra ◽  
Optical Emission ◽  
High Deposition Rate ◽  
Hydrogen Dilution ◽  
Rf Glow Discharge ◽  
Helium Dilution ◽  
Ft Ir

ABSTRACTFormation of hydrogenated amorphous silicon (a-Si:H) was carried out by rf glow discharge method in the reactive gas systems of silane. By preliminary experiments on a-Si:H for helium dilution, a relatively high deposition rate up to 2–3 μm/hr was obtained. In order to investigate the opto-electronic properties on a-Si:H films due to different dilution of helium or hydrogen, measurements on optical band gap Eop, electric conductivity and FT-IR were done. Optical emission spectra were also observed. Optical band gap value Eop on a-Si:H film for SiH4 (10%) -He (90%) was nearly constant about 1.73 eV, while that for SiH4 (10%) -H2 (90%) was increased from 1.75 eV to 1.78 eV with increase of residence time of silane molecule and it was relatively high. From the experimental results of FT-IR, ratio of bonding mode of SiH to (SiH+SiH2) for hydrogen dilution was about 90% and higher than that for helium dilution, while hydrogen concentration in the film for SiH4 (10%) -H2 (90%) was less than 10% and that for SiH4 (10%) -He (90%) was 20–30%.

scholarly journals A Novel Poly{(2,5-diyl furan) (benzylidene)}: A New Synthetic Approach and Electronic Properties

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
Abdelkader Belmokhtar ◽  
Ahmed Yahiaoui ◽  
Aïcha Hachemaoui ◽  
Benyoucef Abdelghani ◽  
Nabahat Sahli ◽  
...  
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Conjugated Polymer ◽  
Optical Band Gap ◽  
Synthetic Approach ◽  
Polar Solvents ◽  
Simple Method ◽  
Sheet Silicate ◽  
Ft Ir ◽  
Silicate Clay

A new conjugated aromatic poly[(furan-2, 5-diyl)-co-(benzylidene)] has been prepared by polycondensation of benzaldehyde and furan catalyzed by Maghnite-H+. Maghnite-H+ is a montmorillonite sheet silicate clay, which exchanged with protons. These polymers can be dissolved in high polar solvents such as DMSO, DMF, THF, or CHCl3 A kind of band-gap conjugated poly[(furan-2, 5-diyl)-co-(benzylidene)] has been synthesized by a simple method and characterized by 1HNMR, 13CNMR, FT-IR, and UV-Vis. The result reveals that the band-gap of the PFB conjugated polymer has an optical band gap of 2.2 eV.

Research on Nanocrystalline Silicon Film Solar Cells

2011 ◽  
Vol 347-353 ◽  
pp. 870-873
Author(s):  
Chun Rong Xue
Keyword(s):  
Grain Size ◽  
Solar Cells ◽  
Band Gap ◽  
Optical Band Gap ◽  
Volume Fraction ◽  
Silicon Film ◽  
Nanocrystalline Silicon ◽  
Processing Parameters ◽  
Crystalline Volume Fraction ◽  
Hydrogen Dilution

Nanocrystalline silicon film has become the research hit of today’ s P-V solar technology. It’s optical band gap was controlled through changing the grain size and crystalline volume fraction for the quanta dimension effect. The crystalline volume fraction in nc-Si:H is modulated by varying the hydrogen concentration in the silane plasma. Also, the crystallinity of the material increases with increasing hydrogen dilution ratio, the band tail energy width of the nc-Si:H concurrently decreases. Two sets of nc-Si:H solar cells were made with different layer thicknesss, their electronic and photonic bandgap, absorption coefficient, optical band gap, nanocrystalline grain size(D), and etc have been stuied. In addition, we discussed the relationship between the stress of nc-Si thin films and H2 ratio. At last nc-Si:H solar cells have been designed and prepared successfully in the optimized processing parameters.

scholarly journals Synthesis of Fluorene Based Alternating Copolymers using Direct Arylation Polymerization

2021 ◽  
Vol 33 (2) ◽  
pp. 393-398
Author(s):  
Mohd Sani Sarjadi ◽  
Yap Leong Khen ◽  
Xin Lin Wong ◽  
Zuhair Jamain ◽  
Md Lutfor Rahman
Keyword(s):  
Solar Cell ◽  
Band Gap ◽  
Active Layer ◽  
Optical Band Gap ◽  
Direct Arylation ◽  
Low Band Gap ◽  
Alternating Copolymers ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Direct Arylation Polymerization

Many researches have been done to obtain a low band gap and high Polymeric solar cell (PSCs) polymer either by creating new polymer or revising reported polymers from previous studies. In present work, two new copolymers were synthesized through direct arylation polymerization to produce poly(9,9-didodecylfluorene-alt-benzo[c][1,2,5]thiadiazole (P1) and poly(9,9-didodecylfluorene-altthieno[ 3,2-b]thiophene) (P2). The P1 and P2 are donor-accepter copolymers. P1 and P2 were compared to investigate its suitability to be applied in PSCs. The polymers obtained were characterized using FT-IR, NMR and UV-Vis spectroscopy. P1 shows two adsorption bands at λmax1 = 243 nm and λmax2 = 320 nm, whereas P2 also shows two adsorption bands at λmax1 = 243 nm and λmax2 = 427 nm. The optical band gap was calculated, P1 enabled band gap of 3.88 eV while P2 showed band gap of 2.91 eV. This work could be provided an insight to design and synthesize more efficient fluorene-based copolymers as active layer of PSCs in due course.

Upconversion Luminescence and Optical Studies of Nd3+ in Bismuth Borate Glasses

2013 ◽  
Vol 770 ◽  
pp. 153-156
Author(s):  
Onanong Chamlek ◽  
Pruittipol Limkitjaroenporn ◽  
Hong Joo Kim ◽  
Jakrapong Kaewkhao
Keyword(s):  
Energy Level ◽  
Band Gap ◽  
Glass Matrix ◽  
Optical Band Gap ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Borate Glasses ◽  
Optical Studies ◽  
Melt Quenching ◽  
Bismuth Borate

Neonymium doped bismuth borate glasses with composition 50Bi2O3 : (50-x)B2O3: xNd2O3 (where x = 0.5, 1.0, 1.5, 2.0 and 2.5 mol%) have been prepared by melt quenching technique. The optical and upconversion luminescence properties of glasses were investigated. The nine absorption peaks were observed, correspond with Nd3+ energy level in glass. The optical band gap decreased with increasing Nd2O3 concentration due to the increase of non-bridging oxygen (NBOs) in glass matrix. The upconversion luminescence emission spectra shows peak at 393 nm, assign to 4D3/24I11/2 transition.

scholarly journals Thermal, Electrical, and Optical Properties of Synthesized (1E, 2E)-(4-bromophenyl)(hydroxyimino)acetaldehyde Oxime Complexes

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Emin Karapinar ◽  
Orhan Karabulut ◽  
Nazan Karapinar
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Conductivity Measurements ◽  
Energy Band Gap ◽  
Temperature Dependent ◽  
Electrical And Optical Properties ◽  
Analysis Techniques ◽  
Temperature Dependent Conductivity ◽  
Ft Ir ◽  
Thermal Analysis Techniques

The (1E, 2E)-(4-bromophenyl)(hydroxyimino)acetaldehyde oxime complexes, [ML2], M = Co(II), Cu(II), and Ni(II), were synthesized and characterized by elemental analysis, magnetic susceptibility, FT-IR spectra, and thermal analysis techniques. The optical band gap of this ligand and its complexes were determined by UV-vis spectrophotometer in the wavelength range 300–800 nm. A decrease in the energy band gap of the [CoL2], [NiL2], and [CuL2] complexes has been observed compared with LH ligand. Temperature-dependent conductivity measurements showed that all samples behave like semiconductor. Activation energies calculated from Arrhenius plots showed that the conduction occurs via both intramolecular and the intermolecular processes.

Structure and Optical Properties of Quantum Confined Pure and Cu Doped SnO2

2020 ◽  
Vol 1159 ◽  
pp. 60-66
Author(s):  
J.R. Sheeba ◽  
Sathasivam Radhika ◽  
C.M. Padma
Keyword(s):  
Band Gap ◽  
Tin Oxide ◽  
Optical Band Gap ◽  
Green Emission ◽  
Precipitation Method ◽  
Rutile Structure ◽  
Tetragonal Rutile Structure ◽  
Ft Ir ◽  
Tin Oxide Nanoparticles ◽  
Co Precipitation

Pure and copper doped tin oxide nanoparticles were synthesized by co-precipitation method and are characterized by XRD, SEM, EDAX, UV-Visible, photoluminescence, and FT-IR analysis techniques. Tetragonal rutile structure is confirmed from XRD and the crystallite size is found to be between 3.8nm and 4.8nm. The optical band gap is observed from UV-Vis spectrum and is found to be 3.99eV and 3.93eV for tin oxide and copper doped tin oxide respectively. The optical band gap of pure and Copper doped tin oxide were blue shifted due to quantum confinement. Photoluminescence spectrum shows UV, blue and green emission peaks.

Hydrogen Dilution Influence on the SIC Films Optical and Micro-Structural Properties as the Window Layer of P-i-n Solar Cell

2011 ◽  
Vol 216 ◽  
pp. 266-270
Author(s):  
Bao Yu Xu ◽  
Hui Dong Yang ◽  
Bo Huang ◽  
Jun Dai Shi
Keyword(s):  
Thin Films ◽  
Solar Cell ◽  
Band Gap ◽  
Structural Properties ◽  
Optical Band Gap ◽  
Optimal Growth ◽  
Window Layer ◽  
Dilution Ratio ◽  
Hydrogen Dilution ◽  
Sic Films

The SiC thin films as the window layer was prepared by PECVD technology in this article, investigated the influence of hydrogen dilution on the optical and micro-structural properties of SiC thin films, Analyzed optical band-gap，deposition rate and surface morphology under different hydrogen dilution ratio, found the optimal growth craft under the same conditions. The results showed that the optical band-gap of the window layer achieved the widest 2.2ev when hydrogen dilution rate was 6.25.

Crystal structure, electronic properties and optical band gap of KLa(1−x)Eux(PO3)4

2014 ◽  
Vol 609 ◽  
pp. 222-227 ◽  
Author(s):  
M. Ferhi ◽  
K. Horchani-Naifer ◽  
C. Bouzidi ◽  
H. Elhouichet ◽  
M. Ferid
Keyword(s):  
Crystal Structure ◽  
Band Gap ◽  
Electronic Properties ◽  
Optical Band Gap

Optical Studies of Physically Deposited Nano-Ag2Te Thin Films

2011 ◽  
Vol 319-320 ◽  
pp. 185-192
Author(s):  
M. Pandiaraman ◽  
N. Soundararajan ◽  
R. Ganesan
Keyword(s):  
Particle Size ◽  
Band Gap ◽  
Optical Band Gap ◽  
Average Particle Size ◽  
High Vacuum ◽  
Emission Spectra ◽  
Average Particle ◽  
Potential Applications ◽  
Evaporation Technique ◽  
Better Than

Silver telluride (Ag2Te), I-VI semiconductor compound with potential applications in various advanced fields. Ag2Te nano films of thickness between 16 nm and 145 nm prepared by thermal evaporation technique at high vacuum better than 2x105 mbar. These films are found to exhibit polycrystalline nature with monoclinic structure from their XRD studies. The average particle size of these films are found to be around 24 nm using the Debye-Scherrer’s formula From AFM measurements, the average particle size is around 24 nm. The emission spectra of these films were recorded and analysed to determine its optical band gap. Optical band gap of Ag2Te varies from 1.6 eV to 1.8 eV with respect to their corresponding thicknesses of films.

IN-SITU SPECTRAL ANALYSIS OF VERY HIGH FREQUENCY GLOW DISCHARGE (VHF-GD)

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4475-4478 ◽  
Author(s):  
HUIDONG YANG ◽  
CHUNYA WU ◽  
SHAOZHENG XIONG ◽  
YAOHUA MAI ◽  
HONGBO LI ◽  
...  
Keyword(s):  
Excitation Frequency ◽  
Emission Spectra ◽  
Optical Emission ◽  
Excitation Power ◽  
Dilution Ratio ◽  
Very High Frequency ◽  
Hydrogen Dilution ◽  
Optical Emission Spectra ◽  
Very High

The intensities of SiH*, [Formula: see text] and H* of VHF-GD for depositing μc-Si:H were much higher than those of RF-GD for depositing a-Si:H. The SiH* intensity of VHF-GD became higher than its Si* intensity as the hydrogen dilution ratio decreased. The influences of the hydrogen dilution ratio on the plasma optical emission spectra also depended on the reaction pressure, the excitation power as well as the excitation frequency.

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