Infrared Spectra of Electronically Doped Polythiophene

2016 ◽  
Vol 1141 ◽  
pp. 222-231
Author(s):  
Hitesh Parmar ◽  
R.K. Shah ◽  
A.T. Oza
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Infrared Spectra ◽  
Small Polaron ◽  
Ftir Spectra ◽  
Polaron Model ◽  
Chemical Company ◽  
Electronic Doping ◽  
Semiconducting Property

Polythiophene was prepared by oxidation of thiophene. It was electronically doped with organic acceptors such as TCNE, TCNQ, DDQ, Chloranil and kI-I2. The FTIR spectra revealed only little change of intermolecular band gap of about 0.21ev of polythiophene .However, polythiophene (pure) obtained from chemical company revealed degenerate semiconducting property. The electronic doping with the organic acceptors and kI-I2 revealed optical properties in small polaron model in the FTIR range. Thus both non-degenerate and degenerate polythiophenes were studied with 60% doping of organic acceptors.

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

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.

scholarly journals Electronic and optical properties of vacancy ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; and X = Cl, Br, I): a first principles study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Faizan ◽  
K. C. Bhamu ◽  
Ghulam Murtaza ◽  
Xin He ◽  
Neeraj Kulhari ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Dielectric Constants ◽  
Maximum Efficiency ◽  
Exchange Potential ◽  
Double Perovskites ◽  
Electronic And Optical Properties

AbstractThe highly successful PBE functional and the modified Becke–Johnson exchange potential were used to calculate the structural, electronic, and optical properties of the vacancy-ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; X = Cl, Br, and I) using the density functional theory, a first principles approach. The convex hull approach was used to check the thermodynamic stability of the compounds. The calculated parameters (lattice constants, band gap, and bond lengths) are in tune with the available experimental and theoretical results. The compounds, Rb2PdBr6 and Cs2PtI6, exhibit band gaps within the optimal range of 0.9–1.6 eV, required for the single-junction photovoltaic applications. The photovoltaic efficiency of the studied materials was assessed using the spectroscopic-limited-maximum-efficiency (SLME) metric as well as the optical properties. The ideal band gap, high dielectric constants, and optimum light absorption of these perovskites make them suitable for high performance single and multi-junction perovskite solar cells.

scholarly journals Flexible Methyl Cellulose/Polyaniline/Silver Composite Films with Enhanced Linear and Nonlinear Optical Properties

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1225
Author(s):  
Ali Atta ◽  
Mostufa M. Abdelhamied ◽  
Ahmed M. Abdelreheem ◽  
Mohamed R. Berber
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Nonlinear Optical ◽  
Composite Films ◽  
Methyl Cellulose ◽  
Carbon Cluster ◽  
Nonlinear Susceptibility ◽  
Optical Parameters ◽  
Flexible Polymer

In order to potentiate implementations in optical energy applications, flexible polymer composite films comprising methyl cellulose (MC), polyaniline (PANI) and silver nanoparticles (AgNPs) were successfully fabricated through a cast preparation method. The composite structure of the fabricated film was confirmed by X-ray diffraction and infrared spectroscopy, indicating a successful incorporation of AgNPs into the MC/PANI blend. The scanning electron microscope (SEM) images have indicated a homogenous loading and dispersion of AgNPs into the MC/PANI blend. The optical parameters such as band gap (Eg), absorption edge (Ed), number of carbon cluster (N) and Urbach energy (Eu) of pure MC polymer, MC/PANI blend and MC/PANI/Ag films were determined using the UV optical absorbance. The effects of AgNPs and PANI on MC polymer linear optical (LO) and nonlinear optical (NLO) parameters including reflection extinction coefficient, refractive index, dielectric constant, nonlinear refractive index, and nonlinear susceptibility are studied. The results showed a decrease in the band gap of MC/PANI/AgNPs compared to the pure MC film. Meanwhile, the estimated carbon cluster number enhanced with the incorporation of the AgNPs. The inclusion of AgNPs and PANI has enhanced the optical properties of the MC polymer, providing a new composite suitable for energy conversion systems, solar cells, biosensors, and nonlinear optical applications.

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.

Structural and Optical Properties of (PVA/PVP:Sr2NO3) Nanocomposites

2021 ◽  
Vol 19 (4) ◽  
pp. 27-37
Author(s):  
Doaa E. Al-Kateb ◽  
Ali R. Abdulridha
Keyword(s):  
Optical Properties ◽  
Energy Gap ◽  
Ftir Spectra ◽  
Structural And Optical Properties ◽  
Casting Method ◽  
Forbidden Transitions ◽  
Nanoparticles Concentration

In this study preparing and investigating of the (PVA/PVP:Sr2NO3) nanocomposites films by using casting method with different concentration of Sr2NO3 as (0, 1, 3, 5, and 7 wt. %). Optical properties obtained by UV-Vis spectrometer, OM and FTIR spectra have been revealed in this study, the absorbance increased by increasing of Sr2NO3 nanoparticles concentrations, the energy-gap (allowed and forbidden) transitions decreased by increasing of the nanoparticles concentration.

scholarly journals First-Principles Study on the Stabilities, Electronic and Optical Properties of GexSn1-xSe Alloys

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 876 ◽  
Author(s):  
Qi Qian ◽  
Lei Peng ◽  
Yu Cui ◽  
Liping Sun ◽  
Jinyan Du ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Band Gap ◽  
Electronic Properties ◽  
First Principles ◽  
Future Application ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Direct Bandgap ◽  
The Future

We systematically study, by using first-principles calculations, stabilities, electronic properties, and optical properties of GexSn1-xSe alloy made of SnSe and GeSe monolayers with different Ge concentrations x = 0.0, 0.25, 0.5, 0.75, and 1.0. Our results show that the critical solubility temperature of the alloy is around 580 K. With the increase of Ge concentration, band gap of the alloy increases nonlinearly and ranges from 0.92 to 1.13 eV at the PBE level and 1.39 to 1.59 eV at the HSE06 level. When the Ge concentration x is more than 0.5, the alloy changes into a direct bandgap semiconductor; the band gap ranges from 1.06 to 1.13 eV at the PBE level and 1.50 to 1.59 eV at the HSE06 level, which falls within the range of the optimum band gap for solar cells. Further optical calculations verify that, through alloying, the optical properties can be improved by subtle controlling the compositions. Since GexSn1-xSe alloys with different compositions have been successfully fabricated in experiments, we hope these insights will contribute to the future application in optoelectronics.

scholarly journals The influence of calcination temperature on structural and optical properties of ZnO nanoparticles via simple polymer synthesis route

2017 ◽  
Vol 49 (3) ◽  
pp. 263-275 ◽  
Author(s):  
Ibrahim Alibe ◽  
Amin Matori ◽  
Elias Saion ◽  
Alibe Ali ◽  
Mohd Zaid
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Calcination Temperature ◽  
Wide Band ◽  
Polymer Synthesis ◽  
Structural And Optical Properties ◽  
Zno Nps ◽  
Wide Band Gap ◽  
Hexagonal Shape ◽  
Particle Size Increase

A simple polymer synthesis was used to successfully synthesized Zinc Oxide Nanoparticles (ZnO NPs), and the influence of the different calcination temperature on the structural, and optical properties of the material was observed using several techniques. The formation of ZnO NPs was confirmed by FT?IR, EDX, XRD, FESEM and TEM images upon calcination from 500?750?C. The FESEM images showed the ZNO NPs synthesized possessed a hexagonal shape and tended to become larger at higher calcination temperature. The XRD and FTIR revealed the precursor to be amorphous at room temperature but transform to a crystalline structure during the process of calcination. The crystalline and particle size increase as the temperature was increased. The crystalline size was between 24?49 nm for all samples calcined at 500?750?C. The optical properties obtained by UV?vis reflectance spectrometer have further confirmed the formation of ZnO NPs. The band gap exhibits typical ZnO wide band gap, and the values decrease with an increase in calcination temperature.

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