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Canlin Ou, Abhijeet Laxman Sangle, Anuja Datta, Qingshen Jing, Tommaso Busolo, Thomas Chalklen, Vijay Narayan, Sohini Kar-Narayan
Thermoelectric materials, capable of interconverting heat and electricity, are attractive for applications in thermal energy harvesting as a means to power wireless sensors, wearable devices and portable electronics. However, traditional inorganic thermoelectric materials pose significant challenges due to high cost, toxicity, scarcity, as well as brittleness particularly when it comes to applications requiring flexibility. Here, we investigate organic-inorganic nanocomposites that have been developed from bespoke inks which are printed via an aerosol jet printing method onto flexible substrates...
May 18, 2018: ACS Applied Materials & Interfaces
Cheng Chang, Minghui Wu, Dongsheng He, Yanling Pei, Chao-Feng Wu, Xuefeng Wu, Hulei Yu, Fangyuan Zhu, Kedong Wang, Yue Chen, Li Huang, Jing-Feng Li, Jiaqing He, Li-Dong Zhao
Thermoelectric technology enables the harvest of waste heat and its direct conversion into electricity. The conversion efficiency is determined by the materials figure of merit ZT Here we show a maximum ZT of ~2.8 ± 0.5 at 773 kelvin in n-type tin selenide (SnSe) crystals out of plane. The thermal conductivity in layered SnSe crystals is the lowest in the out-of-plane direction [two-dimensional (2D) phonon transport]. We doped SnSe with bromine to make n-type SnSe crystals with the overlapping interlayer charge density (3D charge transport)...
May 18, 2018: Science
Woosuck Shin, Tomoyo Goto, Daisuke Nagai, Toshio Itoh, Akihiro Tsuruta, Takafumi Akamatsu, Kazuo Sato
Inflammable breath gases such as H₂ and CH₄ are used as bio markers for monitoring the condition of the colon. However, their typical concentrations of below 100 ppm pose sensitivity and selectivity challenges to current gas sensing systems without the use of chromatography. We fabricated a compact, gas-selective thermoelectric array sensor (TAS) that uses micro-machined sensor devices with three different combustion catalysts to detect gases such as H₂, CO, and CH₄ in breath. Using Pt/Pt-W thin-film micro-heater meanders, Pd/Al₂O₃, Pt,Pd,Au/Co₃O₄, and Pt/Al₂O₃ catalysts were heated to 320, 200, and 125 °C, respectively, and the gas sensing performances of the TAS for each gas and for a model breath gas mixture of 100 ppm H₂, 25 ppm CO, 50 ppm CH₄, and 199 ppm CO₂ in air were investigated...
May 16, 2018: Sensors
Jiayue Tong, Matthew C Conte, Thomas Goldstein, K Sigfrid Yngvesson, Joseph C Bardin, Jun Yan
Graphene, a single atomic layer of covalently bonded carbon atoms, has been investigated intensively for optoelectronics and represents a promising candidate for high-speed electronics. Here we present a microwave mixer constructed as an asymmetrically-contacted two-terminal graphene device based on the thermoelectric effect. We report a 50 GHz (minimum) mixer bandwidth as well as 130 V/W extrinsic direct-detection responsivity. Anomalous second-harmonic generation due to self-mixing in our graphene detector is also observed...
May 16, 2018: Nano Letters
Weihong Gao, Zhenyou Wang, Jin Huang, Zihang Liu
Thermoelectric conversion from low-grade heat to electricity is regarded as the highly reliable and environmentally friendly technology in energy harvesting area. However, how to develop efficient thermoelectric materials using a simple fabrication method is still a critical challenge in thermoelectric community. Here we first fabricate the high thermoelectric performance of Ca doped AgSbSe2 with hierarchical microstructure using a facile approach, namely mechanical alloying (for only 30 minutes) and quick hot pressing method...
May 16, 2018: ACS Applied Materials & Interfaces
Pabitra Narayan Samanta, Jerzy Leszczynski
The thermoelectric transport properties of a metal-ceramic interface based on Al and γ-Al2O3 are explored by employing the non-equilibrium Green's function formalism (NEGF) coupled with density functional theory (DFT). However, to acquire the phonon thermal conductance, the parameterized ReaxFF potential is utilized for computing the intrinsic force constants of propagating phonons across the interface. Several interfacial electronic properties such as the charge transfer, the potential barrier, and the atomic orbital overlap are critically analyzed based on the DFT derived results of the electrostatic difference potential, the electron density difference, and the spin-polarized density of states in the fully relaxed structure of the interface...
May 16, 2018: Physical Chemistry Chemical Physics: PCCP
Sarah Guerin, Tofail A M Syed, Damien Thompson
Collagen piezoelectricity has been the focus of a large number of experimental and theoretical studies for over fifty years. Less is known about the piezoelectric properties of its building blocks, in particular but not limited to, proline and hydroxyproline. Spurred by the recent upsurge of interest in piezoelectricity in organic crystals including our own report of unprecedentedly high piezoelectricity in amino acid glycine, we predict and measure the piezoelectric properties of collagen subcomponents in single crystalline forms and the collagen-like alanine-hydroxyproline-glycine trimer peptide...
May 14, 2018: Nanoscale
I Pletikosić, F von Rohr, P Pervan, P K Das, I Vobornik, R J Cava, T Valla
The success of black phosphorus in fast electronic and photonic devices is hindered by its rapid degradation in the presence of oxygen. Orthorhombic tin selenide is a representative of group IV-VI binary compounds that are robust and isoelectronic and share the same structure with black phosphorus. We measure the band structure of SnSe and find highly anisotropic valence bands that form several valleys having fast dispersion within the layers and negligible dispersion across. This is exactly the band structure desired for efficient thermoelectric generation where SnSe has shown great promise...
April 13, 2018: Physical Review Letters
I-Ju Chen, Adam Burke, Artis Svilans, Heiner Linke, Claes Thelander
In the past decade, there has been significant interest in the potentially advantageous thermoelectric properties of one-dimensional (1D) nanowires, but it has been challenging to find high thermoelectric power factors based on 1D effects in practice. Here we point out that there is an upper limit to the thermoelectric power factor of nonballistic 1D nanowires, as a consequence of the recently established quantum bound of thermoelectric power output. We experimentally test this limit in quasiballistic InAs nanowires by extracting the maximum power factor of the first 1D subband through I-V characterization, finding that the measured maximum power factors conform to the theoretical limit...
April 27, 2018: Physical Review Letters
Lihong Huang, Junchen Wang, Xi Chen, Ran He, Jing Shuai, Jianjun Zhang, Qinyong Zhang, Zhifeng Ren
NbCoSb with nominal 19 valence electrons, and is supposed to be metallic, has recently been reported to also exhibit the thermoelectric properties of a heavily doped n-type semiconductor. In this study, we prepared Co-rich NbCo1+ x Sb samples ( x = 0, 0.2, 0.3, 0.4, 0.5), and their phase compositions, microstructures and thermoelectric properties were investigated. The Seebeck coefficient increased a great deal with increasing x , due to decreasing carrier concentration, and the total thermal conductivity reduced mainly because of declining κ e ...
May 11, 2018: Materials
Ananya Banik, Subhajit Roychowdhury, Kanishka Biswas
Lead chalcogenides and their alloys belong at the heart of thermoelectrics due to their large thermoelectric figure of merit (zT). However, recent research has shown a limitation in the use of lead (Pb)-based materials due to their toxicity and efforts have been made to produce non-toxic analogues of lead chalcogenides. Tin chalcogenides have been predicted to be promising for this purpose due to their unique electronic structure and phonon dispersion properties. Here, we discuss the journey of tin chalcogenides in the field of thermoelectrics and topological materials with the main emphasis on the bonding, crystal structures, electronic band structures, phonon dispersion and thermoelectric properties...
May 11, 2018: Chemical Communications: Chem Comm
Yajing Sun, Zhigang Shuai, Dong Wang
Few-layered arsenic-phosphorus alloys, AsxP(1-x), with a puckered structure have been recently synthesized and demonstrated with fully tunable band gaps and optical properties. It is predicted that the carrier mobility of monolayer AsP compounds is even higher than that of black phosphorene (b-P). The anisotropic and orthogonal electrical and thermal transport properties of the puckered group VA elements make them intriguing materials for thermoelectric applications. Herein, we investigated the thermal transport properties of AsP based on first-principles molecular dynamics and the Boltzmann transport equation...
May 10, 2018: Physical Chemistry Chemical Physics: PCCP
Hyeunhwan An, Dale Karas, Byung-Wook Kim, Sarah Trabia, Jaeyun Moon
Flexible thermoelectric (TE) materials, which are devices that convert thermal gradients to electrical energy, have attracted interest for practical energy-harvesting/recovery applications. However, as compared with p-type materials, the progress on the development of n-type TE flexible materials has been slow due to difficulties involved in n-type doping techniques. This study used high mobility carbon nanotubes (CNTs) to a uniformly mixed hybrid-composite, resulting in an enhanced power factor by increasing electrical conductivity...
July 6, 2018: Nanotechnology
Travis G Novak, Hosun Shin, Jungmo Kim, Kisun Kim, Ashraful Azam, Chien Viet Nguyen, Sun Hwa Park, Jae Yong Song, Seokwoo Jeon
In recent years, two-dimensional black phosphorus (BP) has seen a surge of research due to its unique optical, electronic, and chemical properties. BP has also received interest as a potential thermoelectric material due to its high Seebeck coefficient and excellent charge mobility, but further development is limited by the high cost and poor scalability of traditional BP synthesis techniques. In this work, high quality BP is synthesized using a low-cost method and utilized in a PEDOT:PSS film to create the first ever BP composite thermoelectric material...
May 9, 2018: ACS Applied Materials & Interfaces
M E Manley, P J Stonaha, D L Abernathy, S Chi, R Sahul, R P Hermann, J D Budai
Controlling the thermal energy of lattice vibrations separately from electrons is vital to many applications including electronic devices and thermoelectric energy conversion. To remove heat without shorting electrical connections, heat must be carried in the lattice of electrical insulators. Phonons are limited to the speed of sound, which, compared to the speed of electronic processes, puts a fundamental constraint on thermal management. Here we report a supersonic channel for the propagation of lattice energy in the technologically promising piezoelectric mineral fresnoite (Ba2 TiSi2 O8 ) using neutron scattering...
May 8, 2018: Nature Communications
Z Sartipi, J Vahedi
The thermoelectric transport through a benzene molecule with three metallic terminals is discussed. Using general local and non-local transport coefficients, we investigated different conductance and thermopower coefficients within the linear response regime. Based on the Onsager coefficients which depend on the number of terminal efficiencies, efficiency at maximum power is also studied. In the three-terminal setup with tuning temperature differences, a great enhancement of the figure of merit is observed...
May 7, 2018: Journal of Chemical Physics
Wei Shi, Sanyin Qu, Hongyi Chen, Yanling Chen, Qin Yao, Lidong Chen
Conventional syntheses of polymer-inorganic composite thermoelectric materials suffer major problems such as inhomogeneity, large particle size and oxidation that result in ineffective loading. New technologies are demanded in order to further enhance the performance of composite material with even lower inorganic loading. In this work, we discovered a one-step synthesis to fabricate high quality small-sized anions codoped poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonate/Cl-tellurium (PEDOT:DBSA/Cl-Te) composite films using a series of novel Te (IV)-based oxidants...
May 7, 2018: Angewandte Chemie
Zihang Liu, Jifeng Sun, Jun Mao, Hangtian Zhu, Wuyang Ren, Jingchao Zhou, Zhiming Wang, David J Singh, Jiehe Sui, Ching-Wu Chu, Zhifeng Ren
Germanium telluride (GeTe)-based materials, which display intriguing functionalities, have been intensively studied from both fundamental and technological perspectives. As a thermoelectric material, though, the phase transition in GeTe from a rhombohedral structure to a cubic structure at ∼700 K is a major obstacle impeding applications for energy harvesting. In this work, we discovered that the phase-transition temperature can be suppressed to below 300 K by a simple Bi and Mn codoping, resulting in the high performance of cubic GeTe from 300 to 773 K...
May 7, 2018: Proceedings of the National Academy of Sciences of the United States of America
Degang Zhao, Min Zuo, Lin Bo, Yongpeng Wang
In this study, n -type Pd-doped ZrCo1-x Pdx Bi ( x = 0, 0.03, 0.06, 0.09) half-Heusler samples were prepared by arc-melting and rapid hot-pressing sintering. The thermoelectric properties of ZrCo1-x Pdx Bi samples were analyzed and discussed. The results showed that the electrical properties of ZrCo1-x Pdx Bi, including electrical conductivity and the Seebeck coefficient, increase due to the substitution of Pd on Co site. The lattice thermal conductivity of ZrCo1-x Pdx Bi is markedly decreased because of the Pd/Co substitution...
May 4, 2018: Materials
Rita de Cássia Freire Soares da Silva, Darne Germano de Almeida, Pedro Pinto Ferreira Brasileiro, Raquel Diniz Rufino, Juliana Moura de Luna, Leonie Asfora Sarubbo
Due to their amphipathic nature, biosurfactants are multifunctional molecules that have considerable potential in several industries, especially the petroleum industry. In this study, the commercial production of a biosurfactant from Pseudomonas cepacia CCT6659 grown on industrial waste was investigated in a semi-industrial 50-L bioreactor for use in the removal of hydrocarbons from oily effluents. A concentration of 40.5 g/L was achieved in the scale up and the surface tension was reduced to 29 mN/m. The biosurfactant was formulated with an added preservative, tyndallization and the combination of fluent vaporization plus the preservative...
May 3, 2018: Biodegradation
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