scholarly journals Optical and Photoelectrochemical Investigation of Mixed Photoactive Poly 2,2’,5,2’’ ter-thiophene and Poly 2,2 bithiophene. Role of Intermixed Phases Created By the Co-electro-polymerization Process

2019 ◽  
Vol 12 (1) ◽  
pp. 49
Author(s):  
Kasem K. Kasem ◽  
Monica Schultz ◽  
Sarah H. Osman

Fluorine-doped tin oxide (FTO) electrodes modified with polymeric films of poly 2,2 bithiophene (PBth) and/or poly 2,2’,5,2’’-terthiophene (PTerth) were subjected to optical, photoelectrochemical (PEC), and electrochemical impedance spectroscopy (EIS) studies. Electropolymerization of mixed monomers containing bi-thiophene (Bth) and ter-thiophene (Terth) with different ratios resulted in the formation of intermixed phases. The recorded optical and PEC and EIS outcome data show that these intermixed polymer networks do not follow a monotonic relationship with the monomer ratios used to generate them. Optical studies indicate the formation of indirect and direct band gaps in the intermixed phases. Films generated in mixed monomers have greater energy-band tails than those generated from pure monomers. PEC studies indicated that these intermixed phases possess p-p type hole accumulations, evident from the initial sharp rise in photocurrent. EIS results did not support linear relationship between the percent of Bth in monomer mixture and the dielectric-related properties such as barrier energy Wm, hopping frequency (ω hopping), electrical conductivity (σ), and density of state at Fermi level N (EF).

2016 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
John Rawlins ◽  
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Excimer laser coronary atherectomy (ELCA) is a long-established adjunctive therapy that can be applied during percutaneous coronary intervention (PCI). Technical aspects have evolved and there is an established safety and efficacy record across a number of clinical indications in contemporary interventional practice where complex lesions are routinely encountered. The role of ELCA during PCI for thrombus, non-crossable or non-expandable lesions, chronic occlusions and stent under-expansion are discussed in this review. The key advantage of ELCA over alternative atherectomy interventions is delivery on a standard 0.014-inch guidewire. Additionally, the technique can be mastered by any operator after a short period of training. The major limitation is presence of heavy calcification although when rotational atherectomy (RA) is required but cannot be applied due to inability to deliver the dedicated RotaWire™ (Boston Scientific), ELCA can create an upstream channel to permit RotaWire passage and complete the case with RA – the RASER technique.


Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 1758-P
Author(s):  
HUGO MARTIN ◽  
SÉBASTIEN BULLICH ◽  
FABIEN DUCROCQ ◽  
MARION GRALAND ◽  
CLARA OLIVRY ◽  
...  

Soft Matter ◽  
2021 ◽  
Vol 17 (10) ◽  
pp. 2942-2956
Author(s):  
Rishabh D. Guha ◽  
Ogheneovo Idolor ◽  
Katherine Berkowitz ◽  
Melissa Pasquinelli ◽  
Landon R. Grace

We investigated the effect of temperature variation on the secondary bonding interactions between absorbed moisture and epoxies with different morphologies using molecular dynamics simulations.


2021 ◽  
Vol 13 (3) ◽  
pp. 4156-4164
Author(s):  
Mari Napari ◽  
Tahmida N. Huq ◽  
David J. Meeth ◽  
Mikko J. Heikkilä ◽  
Kham M. Niang ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 988
Author(s):  
Chrysa Aivalioti ◽  
Alexandros Papadakis ◽  
Emmanouil Manidakis ◽  
Maria Kayambaki ◽  
Maria Androulidaki ◽  
...  

Nickel oxide (NiO) is a p-type oxide and nitrogen is one of the dopants used for modifying its properties. Until now, nitrogen-doped NiO has shown inferior optical and electrical properties than those of pure NiO. In this work, we present nitrogen-doped NiO (NiO:N) thin films with enhanced properties compared to those of the undoped NiO thin film. The NiO:N films were grown at room temperature by sputtering using a plasma containing 50% Ar and 50% (O2 + N2) gases. The undoped NiO film was oxygen-rich, single-phase cubic NiO, having a transmittance of less than 20%. Upon doping with nitrogen, the films became more transparent (around 65%), had a wide direct band gap (up to 3.67 eV) and showed clear evidence of indirect band gap, 2.50–2.72 eV, depending on %(O2-N2) in plasma. The changes in the properties of the films such as structural disorder, energy band gap, Urbach states and resistivity were correlated with the incorporation of nitrogen in their structure. The optimum NiO:N film was used to form a diode with spin-coated, mesoporous on top of a compact, TiO2 film. The hybrid NiO:N/TiO2 heterojunction was transparent showing good output characteristics, as deduced using both I-V and Cheung’s methods, which were further improved upon thermal treatment. Transparent NiO:N films can be realized for all-oxide flexible optoelectronic devices.


1985 ◽  
Vol 56 ◽  
Author(s):  
F.-C. Su ◽  
S. Levine ◽  
P. E. Vanier ◽  
F. J. Kampas

AbstractAmorphous semiconductor superlattice structures consisting of alternating n-type and p-type doped layers of hydrogenated amorphous silicon (a-Si:H) have been made by silane glow discharge in a single chamber system. These multilayered films show the novel phenomenon of light-induced excess conductivity (LEC) associated with a metastable state having a lifetime of order of days. This report shows that the LEC effect is quite dependent on the specific details of the deposition parameters, namely dilution of the silane with inert gas, substrate temperature and layer thickness. In order to investigate the origin of the LEC effect, argon dilution was used for specific regions of the structure. This experiment shows that the slow states are distributed throughout the layers, and are not concentrated at the interfaces.


2016 ◽  
Vol 30 (20) ◽  
pp. 1650257
Author(s):  
Meng Zhao ◽  
Wenjun Wang ◽  
Jun Wang ◽  
Junwei Yang ◽  
Weijie Hu ◽  
...  

Various Be:O-codoped AlN crystals have been investigated via first-principles calculations to evaluate the role of the different combinations in effectively and efficiently inducing p-type carriers. It is found that the O atom is favored to bond with two Be atoms. The formed Be2:O complexes decrease the acceptor ionization energy to 0.11 eV, which is 0.16 eV lower than that of an isolated Be in AlN, implying that the hole concentration could probably be increased by 2–3 orders of magnitude. The electronic structure of Be2:O-codoped AlN shows that the lower ionization energy can be attributed to the interaction between Be and O. The Be–O complexes, despite failing to induce p-type carriers for the mutual compensation of Be and O, introduce new occupied states on the valence-band maximum (VBM) and hence the energy needed for the transition of electrons to the acceptor level is reduced. Thus, the Be2:O codoping method is expected to be an effective and efficient approach to realizing p-type AlN.


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