Electron and heat transport in porphyrin-based single-molecule transistors with electro-burnt graphene electrodes

• Hatef Sadeghi,
• Sara Sangtarash and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 1413–1420, doi:10.3762/bjnano.6.146

• charge transport by means of an effective tight binding model. Finally, we investigate the thermoelectric properties of the device. Results and Discussion Figure 1 shows the molecular structure of the porphyrin-based single-molecule transistor (SET), which consists of two electro-burnt graphene

• position changes, and interesting features can result close to the HOMO that could be used in thermoelectric devices. Furthermore, they could be split if slightly asymmetric coupling between carbon and nitrogen is applied. Neither the Zn nor the side groups (represented in Figure 6a by “Si”) have an effect

• small as 10 meV increases the thermopower to 475 μV/K. In contrast, the electronic thermal conductance of the device is quite low and does not change significantly with the small variation of the Fermi energy. The thermoelectric figure-of-merit could be high in this device provided the phonon

Enhancing the thermoelectric figure of merit in engineered graphene nanoribbons

• Hatef Sadeghi,
• Sara Sangtarash and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 1176–1182, doi:10.3762/bjnano.6.119

• Hatef Sadeghi Sara Sangtarash Colin J. Lambert Quantum Technology Centre, Department of Physics, Lancaster University, LA1 4YB Lancaster, UK 10.3762/bjnano.6.119 Abstract We demonstrate that thermoelectric properties of graphene nanoribbons can be dramatically improved by introducing nanopores

• . In monolayer graphene, this increases the electronic thermoelectric figure of merit ZTe from 0.01 to 0.5. The largest values of ZTe are found when a nanopore is introduced into bilayer graphene, such that the current flows from one layer to the other via the inner surface of the pore, for which

• values as high as ZTe = 2.45 are obtained. All thermoelectric properties can be further enhanced by tuning the Fermi energy of the leads. Keywords: graphene nanoribbons; quantum transport; thermal conductance; thermoelectric figure of merit; thermopower; Introduction Nowadays, the performance of

Electrical characterization of single molecule and Langmuir–Blodgett monomolecular films of a pyridine-terminated oligo(phenylene-ethynylene) derivative

• Henrry M. Osorio,
• Santiago Martín,
• María Carmen López,
• Santiago Marqués-González,
• Simon J. Higgins,
• Richard J. Nichols,
• Paul J. Low and
• Pilar Cea

Beilstein J. Nanotechnol. 2015, 6, 1145–1157, doi:10.3762/bjnano.6.116

• permit the appearance of new functions and technological applications not possible with conventional semiconductors such as quantum information processing [7], quantum computation [8], thermoelectric energy conversion [9], etc. The study of single-molecule junctions has enormously contributed to our

A simple approach to the synthesis of Cu_1.8S dendrites with thiamine hydrochloride as a sulfur source and structure-directing agent

• Xiaoliang Yan,
• Sha Li,
• Yun-xiang Pan,
• Zhi Yang and
• Xuguang Liu

Beilstein J. Nanotechnol. 2015, 6, 881–885, doi:10.3762/bjnano.6.90

• temperature [4]. Polycrystalline Cu1.8S powder was prepared by mechanical alloying and subsequent spark plasma sintering and it exhibited excellent thermoelectric properties as a p-type sulfide [5]. An aqueous ammonia assisted approach was developed for the synthesis of Cu1.8S with triangular and rod-like

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• Giovanni Pennelli University of Pisa, Dipartimento di Ingegneria dell’Informazione, Via Caruso 16, I-56122 Pisa, Italy 10.3762/bjnano.5.141 Abstract A big research effort is currently dedicated to the development of thermoelectric devices capable of a direct thermal-to-electrical energy

• for high efficiency thermoelectric conversion will be discussed, and a quick review of the most promising materials currently under development will be given. This review paper will put a particular emphasis on nanostructured silicon, which represents a valid compromise between good thermoelectric

• properties on one side and material availability, sustainability, technological feasibility on the other side. The most important bottom-up and top-down nanofabrication techniques for large area silicon nanowire arrays, to be used for high efficiency thermoelectric devices, will be presented and discussed

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

Integration of ZnO and CuO nanowires into a thermoelectric module

• Dario Zappa,
• Simone Dalola,
• Guido Faglia,
• Elisabetta Comini,
• Matteo Ferroni,
• Caterina Soldano,
• Vittorio Ferrari and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2014, 5, 927–936, doi:10.3762/bjnano.5.106

• synthesized and preliminarily investigated as innovative materials for the fabrication of a proof-of-concept thermoelectric device. The Seebeck coefficients, electrical conductivity and thermoelectric power factors (TPF) of both semiconductor materials have been determined independently using a custom

• experimental set-up, leading to results in agreement with available literature with potential improvement. Combining bundles of ZnO and CuO nanowires in a series of five thermocouples on alumina leads to a macroscopic prototype of a planar thermoelectric generator (TEG) unit. This demonstrates the possibility

• of further integration of metal oxide nanostructures into efficient thermoelectric devices. Keywords: copper oxide; nanowires; thermoelectric; zinc oxide; Introduction A thermoelectric generator (TEG) is a device capable of converting a temperature gradient into an electrical voltage difference

Optical and structural characterization of oleic acid-stabilized CdTe nanocrystals for solution thin film processing

• Claudio Davet Gutiérrez-Lazos,
• Mauricio Ortega-López,
• Manuel A. Pérez-Guzmán,
• A. Mauricio Espinoza-Rivas,
• Francisco Solís-Pomar,
• Rebeca Ortega-Amaya,
• L. Gerardo Silva-Vidaurri,
• Virginia C. Castro-Peña and
• Eduardo Pérez-Tijerina

Beilstein J. Nanotechnol. 2014, 5, 881–886, doi:10.3762/bjnano.5.100

• quantum effect based devices [11] such as light emitting diodes [12], biolabeling [13], thermoelectric generators [14] and thin film solar cells [15]. In solar cell technology, colloidal nanocrystals hold promise for producing cheap solar cells with improved conversion efficiency by using quantum effects

Charge and spin transport in mesoscopic superconductors

• M. J. Wolf,
• F. Hübler,
• S. Kolenda and
• D. Beckmann

Beilstein J. Nanotechnol. 2014, 5, 180–185, doi:10.3762/bjnano.5.18

• with a spin-dependent tunnel conductance, as it is the case in our experiment. For this case, large thermoelectric effects driven by the temperature difference between superconductor and ferromagnet have been predicted recently [31][32]. Conclusion We have presented an analysis of our recent

• currents in superconductors may be useful for future superconducting spintronics devices. Further, our analysis of the temperature dependence hints at the importance of new thermoelectric effects in nanoscale superconductor-ferromagnet hybrids. False color scanning electron microscopy image of one of our

Energy-related nanomaterials

• Paul Ziemann and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 678–679, doi:10.3762/bjnano.4.76

• concern fuel cells, Li-based batteries, and organic solar cells, to energy-related applications of nanographite and silicon nanotubes as well as the optimization of thermoelectric materials and electrochemistry-based microscopy. We would like to thank all colleagues for their valuable contributions and

Structural and thermoelectric properties of TMGa₃ (TM = Fe, Co) thin films

• Sebastian Schnurr,
• Ulf Wiedwald,
• Paul Ziemann,
• Valeriy Y. Verchenko and
• Andrei V. Shevelkov

Beilstein J. Nanotechnol. 2013, 4, 461–466, doi:10.3762/bjnano.4.54

• crystalline bulk material exhibits a semiconducting behavior, though with a small gap of 0.3 eV. Also the thermoelectric performance complies with that of metallic glasses: Small negative Seebeck coefficients of the order of −6 μV/K at 300 K with almost linear temperature dependence in the range 10 K ≤ T

• ≤ 300 K. Keywords: amorphous metal films; energy related; intermetallic compounds; nanomaterials; Seebeck coefficient; thermoelectric properties; thin metal films; Introduction Intermetallic compounds usually behave as metals. In some cases, however, when a compound contains both, d- and p-block

• sharp features in the electronic density of states (DOS) close to the Fermi level, which are expected to be quite beneficial for an enhanced thermoelectric response [5][6]; large Seebeck coefficients of −350 μV/K [7] or even −563 μV/K [8] at room temperature were reported for bulk FeGa3. Recently, we

Synthesis and thermoelectric properties of Re₃As_6.6In_0.4 with Ir₃Ge₇ crystal structure

• Valeriy Y. Verchenko,
• Anton S. Vasiliev,
• Alexander A. Tsirlin,
• Vladimir A. Kulbachinskii,
• Vladimir G. Kytin and
• Andrei V. Shevelkov

Beilstein J. Nanotechnol. 2013, 4, 446–452, doi:10.3762/bjnano.4.52

• . Re3As6.6In0.4 behaves as a bad metal or heavily doped semiconductor, with electrons being the dominant charge carriers. It possesses high values of Seebeck coefficient and low thermal conductivity, but relatively low electrical conductivity, which leads to rather low values of the thermoelectric figure of merit

• . Keywords: band-structure calculations; energy conversion; Ir3Ge7 type; solid solution; thermoelectric material; Introduction Thermoelectric materials with good efficiency are highly awaited by modern power engineering. Utilizing either the Seebeck or Peltier effects, it is possible to produce electricity

• from waste heat (e.g., that stemming from combustion in car engines) or to cool an environment under an external power supply. However, the efficiency of these processes depends on the efficiency of the thermoelectric material in question, which is defined by the value of the figure of merit where T

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

• due to theoretical studies predicting a large enhancement of the thermoelectric efficiency, given by the so-called figure of merit ZT, ZT = S2·σ·T/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity and T is the temperature. The power factor (S2σ) of

• these thermoelectric nanomaterials should increase due to quantum size effects and the thermal conductivity should decrease due to enhanced phonon surface scattering [85][86][87][88]. The thermoelectric properties of these Bi-compound materials are anisotropic and are extremely sensitive not only to

• composition and size, but also to the crystallographic orientation of the wires. During synthesis, it is thus important to control these three parameters simultaneously. To achieve a significant enlargement of the thermoelectric efficiency, the diameter of such nanowires should be below 30 nm. Cornelius et al

Effect of deposition temperature on the structural and optical properties of chemically prepared nanocrystalline lead selenide thin films

• Anayara Begum,
• Amir Hussain and
• Atowar Rahman

Beilstein J. Nanotechnol. 2012, 3, 438–443, doi:10.3762/bjnano.3.50

• size [2][3]. PbSe has wide applications in long and mid-wavelength infrared detectors, optical amplifiers, mid-infrared lasers, as thermoelectric materials, and as Pb2+ ion selective sensors [4][5][6][7]. Among the various techniques used to prepare PbSe thin films, such as vacuum evaporation [8

When “small” terms matter: Coupled interference features in the transport properties of cross-conjugated molecules

• Gemma C. Solomon,
• Justin P. Bergfield,
• Charles A. Stafford and
• Mark A. Ratner

Beilstein J. Nanotechnol. 2011, 2, 862–871, doi:10.3762/bjnano.2.95

• Department of Chemistry, Northwestern University, 2145 Sheridan Rd, Evanston, IL 60208, USA 10.3762/bjnano.2.95 Abstract Quantum interference effects offer opportunities to tune the electronic and thermoelectric response of a quantum-scale device over orders of magnitude. Here we focus on single-molecule

• cross-conjugated molecules appears to be significantly more sensitive to perturbations than those observed in equivalent cyclic systems and this needs to be considered if such supernodes are required for molecular thermoelectric devices. Keywords: gDFTB; Hückel model; many-body effects; molecular

• strategies to control the flow of charge through a molecular circuit. Thermoelectric effects are also strongly influenced by the presence of interference features, and enhancement is predicted in the vicinity of nodes and peaks [15][16]. In certain molecules composed of node-possessing subunits, multiple

Simple theoretical analysis of the photoemission from quantum confined effective mass superlattices of optoelectronic materials

• Debashis De,
• Sitangshu Bhattacharya,
• S. M. Adhikari,
• A. Kumar,
• P. K. Bose and
• K. P. Ghatak

Beilstein J. Nanotechnol. 2011, 2, 339–362, doi:10.3762/bjnano.2.40

• , be written as [24] where n0 and EF are applicable for bulk samples. The thermoelectric power of the carriers in semiconductors in the presence of a classically large magnetic field is independent of scattering mechanisms and is determined only by their energy band spectra [25]. The magnitude of the

• thermoelectric power G can be written under the condition of carrier degeneracy [25] as Using Equation 23 and Equation 24, one obtains Therefore, we can experimentally determine LD by knowing the experimental curve of G versus carrier concentration at a fixed temperature. It is evident that the DSL for a system