Article
Chemistry, Multidisciplinary
Kyu Hyoung Lee, Sang-il Kim, Jong-Chan Lim, Jung Young Cho, Heesun Yang, Hyun-Sik Kim
Summary: Band engineering is an effective strategy for improving the electronic transport properties of semiconductors. This article proposes a simple equation that utilizes experimentally determined Seebeck coefficient and carrier concentration to determine the effective mass of thermoelectric materials. This equation is crucial for designing materials with maximized thermoelectric performance.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Lizhong Su, Haonan Shi, Sining Wang, Dongyang Wang, Bingchao Qin, Yuping Wang, Cheng Chang, Li-Dong Zhao
Summary: Thermoelectric materials have the potential for refrigeration and power generation through direct heat-to-electricity conversion. Carrier mobility and Seebeck coefficient are crucial properties of these materials. This study emphasizes the importance of modifying the scattering factor to enhance the electrical properties. Anisotropic scattering factor is found to enhance carrier mobility and Seebeck coefficient in anion-doped n-type tin selenide crystals, suggesting the potential for improving electrical properties. Using this strategy, the average dimensionless figure of merit (ZT(ave)) for iodine-doped SnSe crystals is significantly improved from 0.84 to 1.57 in the temperature range of 300-773 K. These results highlight the critical role of scattering factor and propose a novel perspective for enhancing carrier mobility, offering a new strategy for optimizing thermoelectric performance.
ADVANCED ENERGY MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Yuseong Kim, Byoungnam Park
Summary: We demonstrate an enhanced photo-Seebeck effect in air-stable MAPbI(3) perovskite through optical gating. Illumination by a laser diode leads to a significant increase in both the Seebeck coefficient and electrical conductivity. The n-type MAPbI(3) perovskite with residual PbI2 shows higher Seebeck enhancement and photoconductivity compared to the p-type perovskite. This indicates that the presence of PbI2 accelerates photoinduced charge transfer at the interface, resulting in dedoping and enhanced photo-Seebeck effect.
Article
Materials Science, Multidisciplinary
H. M. Yuan, S. H. Han, R. Hu, W. Y. Jiao, M. K. Li, H. J. Liu, Y. Fang
Summary: This paper proposes a neural network model that can quickly evaluate the Seebeck coefficient at arbitrary carrier concentration. By using only a few elemental properties as input features, the model exhibits high correlation between the real and predicted Seebeck coefficients. The model can be used to screen Heusler compounds for accelerated discovery of new materials with desired Seebeck coefficients.
MATERIALS TODAY PHYSICS
(2022)
Article
Chemistry, Physical
Md Golam Rosul, Mona Zebarjadi
Summary: We studied the thermoelectric properties of bulk MoSe2 at room temperature using first-principles calculations and relaxation time approximation. We found that the cross-plane mobility of this material is two orders of magnitude smaller than the in-plane mobility. The inclusion of van der Waals interactions had minimal effect on the Seebeck coefficient. The computed results were in close agreement with experimental values, indicating the accuracy of the calculations.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Nanoscience & Nanotechnology
Domenic Prete, Valeria Demontis, Valentina Zannier, Maria Jesus Rodriguez-Douton, Lorenzo Guazzelli, Fabio Beltram, Lucia Sorba, Francesco Rossella
Summary: We fabricated dual-gated electric double layer (EDL) field effect transistors based on InAs nanowires gated with an ionic liquid, and performed electrical transport measurements at different temperatures. The study found that adjusting the spatial distribution of ions in the ionic liquid can induce doping in the nanostructures, and the carrier concentration and mobility are significantly affected by the liquid gate voltage changes.
Article
Multidisciplinary Sciences
Zi-Di Yu, Yang Lu, Zi-Yuan Wang, Hio-Ieng Un, Szymon J. Zelewski, Ying Cui, Hao-Yang You, Yi Liu, Ke-Feng Xie, Ze-Fan Yao, Yu-Cheng He, Wen-Bing Hu, Jie-Yu Wang, Henning Sirringhaus, Jian Pei
Summary: The charge transport properties of conjugated polymers are often limited by energetic disorder. Recently, amorphous conjugated polymers with planar backbone conformations and low energetic disorder have been investigated. However, there is a lack of strategy to finely tune the interchain Tr-Tr contacts of these polymers. In this study, excellent conductivity and thermoelectric performance were achieved in polymers based on thiophene-fused benzodifurandione oligo(p-phenylene-vinylene) by reducing the crystallization rate of side chains and controlling the degree of interchain pi-pi contacts.
Article
Chemistry, Multidisciplinary
Hui Li, Zhen Xu, Jian Song, Haoyu Chai, Lili Wu, Lidong Chen
Summary: Chemical doping of donor-acceptor (D-A) polymers is crucial for highly efficient optoelectronic devices. A new D-A polymer, Pg(3)2T-OTz, was designed and synthesized with high carrier concentration and mobility achieved through a single-solution doping method. The research demonstrates that modulation of acceptor strength combined with side-chain engineering is an effective strategy to improve both doping efficiency and carrier transport properties of D-A polymers.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Energy & Fuels
David Krisztian, Ferenc Korsos, Gergely Havasi
Summary: For the first time, the transient, steady-state, and small perturbation photoconductance decay lifetime measurement methods have been successfully combined into a single system. These three modes of operation complement each other and improve the accuracy of each measurement by compensating for their individual limitations. The combination of these methods provides accurate carrier lifetime data and the sum of excess carrier mobilities, which is crucial for high injection levels in modern solar cells where existing mobility models exhibit significant differences.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Chemistry, Physical
M. Sabarinathan, V. Vijay, S. Harish, Y. Hayakawa
Summary: This study reports on the hydrothermally prepared MoS2/Bi2S3 nanocomposites for mid-temperature thermoelectric applications. X-ray photoelectron spectroscopy reveals the change in fermi level of nanocomposites with Bi incorporation and oxidation states of the elements. High-Resolution Transmission Electron Microscope (HR-TEM) clearly indicates the formation of MoS2 nanosheets and Bi2S3 nanowires with the presence of interfaces. The interfacial effect greatly improves the thermoelectric power factor to 900 nW/mK2, nearly 8 times higher than pure MoS2.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
K. P. Mithun, Shalini Tripathi, Ahin Roy, N. Ravishankar, A. K. Sood
Summary: We investigated carrier relaxation dynamics in semiconducting tellurium nanowires using ultrafast time-resolved terahertz spectroscopy. The relaxation process was found to exhibit bi-exponential decay with two time scales depending on the amount of capping agent on the TeNWs surface. A coupled rate equation model was used to quantitatively understand the relaxation mechanisms and the observed temperature-dependent dynamics. Furthermore, the frequency-dependent THz photoconductivity was modeled using the Boltzmann transport equation, revealing the contributions of short range and Coulomb scattering rates in the relaxation process.
Article
Thermodynamics
Arslan Ashfaq, Rasmiah S. Almufarij, M. Yasir Ali, Adnan Ali, Sofia Tahir, Michael M. Sabugaa, Mohamed Abdelsabour Fahmy, Elsammani Ali Shokralla, Ahmed H. Ragab, D. E. El-Refaey, Khalid Mehmood
Summary: In this study, Bi2Se3 thin films were synthesized using a thermal evaporation method and sulfurized for different durations. The structural change from rhombohedral to orthorhombic was confirmed using X-ray diffraction. Raman spectroscopy was used to analyze the atomic vibrational modes of Bi2(Se,S)3 thin films, and scanning electron microscopy was used to observe their surface morphology. The Seebeck coefficient increased from 155.1 to 203.5 μV/K with longer sulfurization time, which was attributed to increased charge carrier concentration and energy filtering effect. The electrical conductivity also improved due to higher charge carrier concentration and the change in crystal structure. The maximum power factor achieved for Bi2(Se,S)3 thin films was 4.86 μWcm-1K-2 at room temperature, indicating a promising approach for commercial thermoelectric material fabrication.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Materials Science, Ceramics
Ubaid Ur Rehman, Jolly Jacob, F. F. Al-Harbi, A. Ashfaq, K. Mahmood, A. Ali, N. Amin, Mongi Amami, S. Hussain, K. Javaid, Salma Ikram, Kashaf ul Sahar
Summary: In this study, the thermoelectric power generation performance of ZnO nanostructures is improved by controlling the Mn doping concentration. Mn doping increases the Seebeck coefficient but decreases the electrical conductivity. The highest thermoelectric power factor value is obtained for the sample doped at x = 0.5.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Multidisciplinary
Xumin Wang, Shaoyun Huang, Ji-Yin Wang, Dong Pan, Jianhua Zhao, H. Q. Xu
Summary: By integrating highly tunable multiple quantum dots with integrated charge sensors on InAs nanowires, the charge states of double quantum dots can be accurately monitored, even in a regime with few electrons.
Article
Chemistry, Inorganic & Nuclear
Salma Ikram, A. Ali, N. Amin, Iqra Tabassam, Mongi Amami, K. Javaid, M. Yasir Ali, K. Mahmood, Aqrab ul Ahmad, Sajid Hussain Siyal
Summary: In this study, the structural and thermoelectric properties of ZnAlS nanoparticles alloy were successfully controlled by varying the concentration of Al atoms. The results showed that the structure quality of the samples decreased with increasing Al atom concentration, while the conductivity and Seebeck coefficient increased. Raman data confirmed the formation of secondary phases.
INORGANIC CHEMISTRY COMMUNICATIONS
(2022)
Review
Physics, Applied
Daniele Caimi, Marilyne Sousa, Siegfried Karg, Cezar B. Zota
Summary: This study demonstrates a scaled III-V FinFET technology integrated on Si substrates, exploring its logic performance under physical gate lengths of 20 nm and fin widths of 15 nm. Additionally, the research shows that the use of source and drain spacers in III-V FETs can significantly improve off-state characteristics and reduce power density while enabling a memory effect.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Neurosciences
Elisabetta Corti, Joaquin Antonio Cornejo Jimenez, Kham M. Niang, John Robertson, Kirsten E. Moselund, Bernd Gotsmann, Adrian M. Ionescu, Siegfried Karg
Summary: A new in-memory computing platform based on coupled VO2 oscillators fabricated in a crossbar configuration on silicon is proposed in this work. The platform shows promising improvements in area density and oscillation frequency, enabling experiments on 4-coupled oscillators. The concept is tested with a VGG13 architecture on the MNIST dataset, achieving performances of 95% in the recognition task.
FRONTIERS IN NEUROSCIENCE
(2021)
Article
Physics, Multidisciplinary
G. Stefanou, F. Menges, B. Boehm, K. A. Moran, J. Adams, M. Ali, M. C. Rosamond, B. Gotsmann, R. Allenspach, G. Burnell, B. J. Hickey
Summary: Through scanning thermal microscopy, the spatial distribution of temperatures in a nanoscale device was mapped, with an analytical model explaining thermal diffusion over the measured temperature range and injector-detector separation. Below 60 K, the characteristic diffusion lengths of Peltier and Joule heat show remarkable differences, possibly due to the onset of ballistic phonon heat transfer in the substrate.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Pengyan Wen, Preksha Tiwari, Svenja Mauthe, Heinz Schmid, Marilyne Sousa, Markus Scherrer, Michael Baumann, Bertold Ian Bitachon, Juerg Leuthold, Bernd Gotsmann, Kirsten E. Moselund
Summary: This study successfully achieved the seamless integration of III-V nanostructures on silicon and demonstrated the performance of scaled and waveguide coupled III-V photodiodes. Furthermore, it was found that the temperature increase during device operation as an emitter was only approximately 15 K according to experimental and simulation results.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Applied
Bernd Gotsmann, Andrea Gemma, Dvira Segal
Summary: This Perspective discusses the concepts, theoretical and experimental progress in the field of quantized phonon transport, with a focus on channels such as molecular systems. It highlights open questions and research opportunities and emphasizes the recent advancements in experimental capabilities.
APPLIED PHYSICS LETTERS
(2022)
Article
Computer Science, Artificial Intelligence
Aida Todri-Sanial, Stefania Carapezzi, Corentin Delacour, Madeleine Abernot, Thierry Gil, Elisabetta Corti, Siegfried F. Karg, Juan Nunez, Manuel Jimenez, Maria J. Avedillo, Bernabe Linares-Barranco
Summary: Brain-inspired computing utilizes devices and architectures that mimic biological functions for adaptive and energy-efficient systems. Oscillatory neural networks (ONNs) are an alternative approach for solving large and complex associative problems based on the dynamics of coupled oscillators. A novel method using subharmonic injection locking (SHIL) is proposed to control oscillatory states in coupled oscillators for pattern recognition in large-scale oscillatory networks.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2022)
Article
Nanoscience & Nanotechnology
Pengyan Wen, Preksha Tiwari, Markus Scherrer, Emanuel Loertscher, Bernd Gotsmann, Kirsten E. Moselund
Summary: This study presents a systematic thermal analysis of InP-on-Si micro- and nanocavity lasers, investigating the use of metal cavities for improving their thermal properties. The results show that the presence of a metal cladding not only increases the overall efficiency in heat dissipation but also causes a much faster temperature response.
Article
Engineering, Electrical & Electronic
Alan Molinari, Federico Balduini, Lorenzo Rocchino, Rafal Wawrzynczak, Marilyne Sousa, Holt Bui, Christian Lavoie, Vesna Stanic, Jean Jordan-Sweet, Marinus Hopstaken, Serguei Tchoumakov, Selma Franca, Johannes Gooth, Simone Fratini, Adolfo G. Grushin, Cezar Zota, Bernd Gotsmann, Heinz Schmid
Summary: The chiral semimetal cobalt monosilicide (CoSi) has excellent topological conductor properties, but its use in nanoscale thin films and devices is challenged by its intrinsic disorder and inhomogeneities, which influence its magnetotransport properties. Through a comprehensive investigation of Co1-xSix thin films with controlled microstructure and chemical composition, we found that the resistivity of the films is insensitive to microstructure and changes from metallic-like to semiconducting-like behavior with increasing silicon content. Various anomalies in the magnetotransport properties are attributed to the influence of structural and chemical disorder. Our study highlights the complexity and challenges of utilizing CoSi in nanoscale thin films and devices.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Multidisciplinary Sciences
Andrea Gemma, Fatemeh Tabatabaei, Ute Drechsler, Anel Zulji, Herve Dekkiche, Nico Mosso, Thomas Niehaus, Martin R. Bryce, Samy Merabia, Bernd Gotsmann
Summary: By combining the break junction technique with a suspended heat-flux sensor, the researchers measured the total thermal and electrical conductance of a single molecule, at room temperature, along with its Seebeck coefficient. The result is in agreement with predictions and opens new opportunities for thermoelectric applications.
NATURE COMMUNICATIONS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Pengyan Wen, Preksha Tiwari, Markus Scherrer, Emanuel Lortscher, Kirsten E. Moselund, Bernd Gotsmann
Summary: The temperature dependence of Raman scattering in nanostructures can be influenced by strain and photoexcited carriers. The Stokes peak linewidth is the most appropriate method for thermal calibration in InP nanostructures.
2022 ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE, ACP
(2022)
Proceedings Paper
Optics
Qian Ding, Pengyan Wen, Bernd Gotsmann, Kirsten E. Moselund, Andreas Schenk
Summary: This article discusses the importance of self-heating effects on power consumption in integrated nanophotonic devices, and investigates the thermal behavior related to traps in a monolithic InP-InGaAs-InP pin-diode through experiments and simulations.
INTEGRATED PHOTONICS PLATFORMS II
(2022)
Article
Chemistry, Multidisciplinary
Fatemeh Tabatabaei, Samy Merabia, Bernd Gotsmann, Mika Prunnila, Thomas A. Niehaus
Summary: This article computes the out of equilibrium current-voltage characteristics and dissipated heat of OPE3 molecular junctions using the DFTB method within NEGF. It analyzes the Peltier cooling power as a function of bias voltage and investigates parameters for optimal cooling performance. The results demonstrate that OPE3 devices are compatible with temperature reductions of several K, and strategies for high-performance cooling applications are briefly discussed.
Letter
Materials Science, Multidisciplinary
Stefania Carapezzi, Gabriele Boschetto, Siegfried Karg, Aida Todri-Sanial
Summary: In this study, we utilized TCAD modeling to simulate the resistive switching effects in VO2 devices induced by heat. We investigated how heat dissipation affects the behavior of VO2 devices and found entangled self-oscillatory behavior of temperature and voltage across the device. These findings provide essential guidelines for the design of VO2 oscillators used in oscillatory neural networks circuits for neuromorphic computing.
MRS COMMUNICATIONS
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Pengyan Wen, Preksha Tiwari, Bernd Gotsmann, Kirsten E. Moselund
Summary: Thermal effects in InP-on-Si nanocavity lasers vary with different pumping strategies. The transient results suggest the significant role of pulse width and period in thermal effects.
2021 IEEE 17TH INTERNATIONAL CONFERENCE ON GROUP IV PHOTONICS (GFP 2021)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
P. Wen, P. Tiwari, K. E. Moselund, B. Gotsmann
Summary: The optimal diameter of InP nanocavity lasers is around 1000 nm when considering both thermal effects and optical confinement. Thinning the underlying SiO2 is the most efficient way to improve the thermal properties of the nanocavity lasers.
2021 INTERNATIONAL CONFERENCE ON NUMERICAL SIMULATION OF OPTOELECTRONIC DEVICES (NUSOD)
(2021)
