A5010824978- Molecular Junctions and Nanostructures
- Graphene research and applications
- Advanced Thermoelectric Materials and Devices
- Quantum and electron transport phenomena
- Organic Electronics and Photovoltaics
- Advanced Thermodynamics and Statistical Mechanics
- Semiconductor Lasers and Optical Devices
- Carbon Nanotubes in Composites
- Advanced Nanomaterials in Catalysis
- Crystallization and Solubility Studies
- Thermal properties of materials
- Semiconductor materials and devices
- Nanowire Synthesis and Applications
- Porphyrin and Phthalocyanine Chemistry
- Electrochemical sensors and biosensors
- Ocular and Laser Science Research
- Advanced biosensing and bioanalysis techniques
- Thermography and Photoacoustic Techniques
- Luminescence and Fluorescent Materials
- Gas Sensing Nanomaterials and Sensors
- Axial and Atropisomeric Chirality Synthesis
- Electrochemical Analysis and Applications
- Electrocatalysts for Energy Conversion
- Photonic and Optical Devices
- Cyclization and Aryne Chemistry
Thi Qar University
2017-2024
University of Warwick
2021
Lancaster University
2016-2018
Lancaster City Council
2017-2018
A key goal in molecular electronics has been to find molecules that facilitate efficient charge transport over long distances. Normally, wires become less conductive with increasing length. Here, we report a series of fused porphyrin oligomers for which the conductance increases substantially length by >10-fold at bias 0.7 V. This exceptional behavior can be attributed rapid decrease HOMO–LUMO gap porphyrins. In contrast, butadiyne-linked moderate inter-ring coupling, normal is found all...
Quantum interference (QI) plays an imperative role in the operation of molecular devices within phase-coherent length, and it is vital to harness patterns QI, i.e., constructive destructive interference. However, size single-molecule device too small compared most gate electrodes. Those gates act like a backgate affect component uniformly. Switching QI same skeleton remains challenging. Here, we develop atomically precise gating strategy that manipulates frontier orbitals components,...
Thermoelectrics as a way to use waste heat is essential in many electronic applications. In this work, the effect of appearance zinc ions center trimer porphyrins on and thermoelectric properties porphyrin molecular junctions was investigated theoretically using combination density functional theory (DFT) methods. Our results show that all have been affected by units. However, findings indicate presence metal ion trimers with one, two, or three significantly affects their thermal...
We have employed the scanning tunneling microscope break-junction technique to investigate single-molecule conductance of a family 5,15-diaryl porphyrins bearing thioacetyl (SAc) or methylsulfide (SMe) binding groups at ortho position phenyl rings (S2 compounds). These substituents lead two atropisomers, cis and trans, for each compound, which do not interconvert in solution under ambient conditions; even high temperatures, isomerization takes several hours (half-life 15 h 140 °C SAc...
If high efficiency organic thermoelectric materials could be identified, then these would open the way to a range of energy harvesting technologies and Peltier coolers using flexible transparent thin-film materials. We have compared properties three zinc porphyrin (ZnP) dimers ZnP monomer found that "edge-over-edge" dimer formed from stacked rings possesses electrical conductance, negligible phonon thermal conductance Seebeck coefficient order 300 μV K−1. These combine yield predicted...
The synthesis of a [60]fullerene-benzyne building block and its further chemical cycloaddition reaction with graphene has resulted in new all-carbon hybrid material which been characterized by TGA, FTIR Raman spectroscopies, XPS as well AFM TEM. Based on computational studies, the formation both [2+2] [4+2] cycloadducts surface is feasible.
Abstract In contrast with conventional single-molecule junctions, in which the current flows parallel to long axis or plane of a molecule, we investigate transport properties M(II)-5,15-diphenylporphyrin (M-DPP) junctions (M=Co, Ni, Cu, Zn divalent metal ions), perpendicular porphyrin. Novel STM-based conductance measurements combined quantum calculations demonstrate that current-perpendicular-to-the-plane (CPP) have three-orders-of-magnitude higher electrical conductances than their...
We investigated the thermoelectric properties of flat-stacked 5,15-diphenylporphyrins containing divalent metal ions Ni, Co, Cu or Zn, which are strongly coordinated with nitrogens pyridyl coated gold electrodes. Changing atom has little effect on thermal conductance due to phonons. The room-temperature Seebeck coefficients these junctions rather high, ranging from 90 μV K-1 for Cu, Ni and Zn-porphyrins -16 Co-porphyrin. These values could be further increased by lowering molecular energy...
There is a worldwide race to convert waste heat useful energy using thermoelectric materials. Molecules are attractive candidates for thermoelectricity because they can be synthesised with the atomic precision, and intriguing properties due quantum effects such as interference induced at room temperature. also expected show low thermal conductance that needed enhance performance of Recently, technological challenge measuring single molecules was overcome. Therefore, it timely develop...
Nanoscale thermoelectricity is an attractive target technology, because it can convert ambient heat into electricity for powering embedded devices in the internet of things.
The calculations of thermoelectric and transport properties have been carried out by using the SIESTA implementation density functional theory (DFT), with a generalized gradient approximation (GGA-PBE) for exchange correlation functionals. In this work we compared FeCP two different configurations. results show that spin-dependent can be affected molecular structure substitution terminal thiol groups plays an important role on transmission junctions. Meanwhile, electrical conductance thermal...
Thermoelectric materials possess the capacity to significantly impact worldwide energy usage by virtue of their capability transform heat into electrical energy. However, majority these exhibit low efficiency. Currently, there are ongoing studies exploring thermoelectric properties molecular junctions and low-dimensional structures. These investigations aim identify evaluate new nanostructure systems that can overcome existing limits. In this study, we have conducted a theoretical comparison...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Alaa Ayad K. Al-mebir, Mohammed D. Noori, Bahjat B. Kadhim; Investigation of the electric thermoelectric properties metallo-phthalocyanine molecular junctions with planar axial configuration. AIP Conference Proceedings 2 February 2023; 2457 (1): 050006. https://doi.org/10.1063/5.0118327 Download citation file:...
The discovery of high-efficiency organic thermoelectric materials has the potential to pave path for various energy-harvesting technologies and development flexible, transparent thin-film Peltier coolers. Our study involves a comparison electrical characteristics four zinc porphyrin configurations. results show that changing linker between diner units an essential effect on conductance thermopower values these structures. Consequently, figure merit ZT will change which means efficiency change.
Abstract The use of graphene and titanium oxide nano-mixtures in a wide variety physical products, such as solar panels, biosensors fuel cells. Owing to the special general properties TiO2 graphene, has huge conductivity sustain is used photo catalyst water moisture solutions bio nano sensors. features, stability low toxicity cost-effectiveness. Primary findings have shown that manufacture system sensor displays great quick reaction glucose be ideal biosensor unit limited by its band gap...
Abstract We present a comparative theoretical study of the electronic and thermoelectric properties staggered eclipsed ferrocene sandwiched between gold electrodes. These molecular junctions have been explored in two different configuration trans cis conformation. In this work, we investigate spin properties, addition to thermoelectrical for all cases. Our results show that there is variation when move from configuration. However, case no effects. Moreover, room temperature electrical...
Abstract In this work, a comparative study is presented that analyses the electrical and thermoelectrical properties of free base-Phthalocyanine (Bare-Pc) Metallo-Phthalocyanine (MPc) molecule sandwiched between gold electrodes. The investigates transmission conductance characteristics Bare-Pc without central metal ion with different transition ions at centre (Pc) such as (Mn, Co, Ni, Zn) in two molecular configurations, cis trans. results reveal changed by varying metal-centre order Co >...
An axial distributed coupling coefficient (ADCC) feedback (DFB) laser diode (LD) in which the (K) has been axially on both sides of phase shift region. The effects injection current normalized gain amplitude, detuning and output power are investigated using transfer matrix method. results show that ADCC DFB exhibits high single mode stability at different currents above threshold main operates close to Bragg wavelength injected current. For optical increased with decreased coefficient.