A5043525781- Advanced Thermoelectric Materials and Devices
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Thermal properties of materials
- Heusler alloys: electronic and magnetic properties
- Thermal Radiation and Cooling Technologies
- Topological Materials and Phenomena
- Perfectionism, Procrastination, Anxiety Studies
- High-pressure geophysics and materials
- Electronic and Structural Properties of Oxides
- 2D Materials and Applications
- Thermal Expansion and Ionic Conductivity
- Advanced Thermodynamics and Statistical Mechanics
- Crystallization and Solubility Studies
- Advanced Chemical Physics Studies
- Perovskite Materials and Applications
- Photorefractive and Nonlinear Optics
- Astronomy and Astrophysical Research
- Laser-Matter Interactions and Applications
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Diffusion and Search Dynamics
- CCD and CMOS Imaging Sensors
- Injection Molding Process and Properties
- Supercapacitor Materials and Fabrication
University of Michigan–Ann Arbor
2015-2024
Ann Arbor Center for Independent Living
2016-2021
Wuhan University of Technology
2018
Chongqing University
2018
Northwest University
2015
Princeton University
2013-2014
Argonne National Laboratory
2013
Worcestershire Royal Hospital
1986
We demonstrate a high solubility limit of >9 mol% for MnTe alloying in SnTe. The electrical conductivity SnTe decreases gradually while the Seebeck coefficient increases remarkably with increasing content, leading to enhanced power factors. room-temperature coefficients Mn-doped are significantly higher than those predicted by theoretical Pisarenko plots pure SnTe, indicating modified band structure. high-temperature Hall data Sn1-xMnxTe show strong temperature dependence, suggestive...
Thermoelectric figure of merit, ZT, exceeding 2.6 at 850 K and copper electromigration inhibition have been demonstrated in indium modified Cu<sub>2</sub>Se.
The discordant Zn and Ga atoms raise the carrier concentration soften phonon modes, resulting in superior performance nanostructured n-type PbTe.
We report on the underlying mechanism that enables SnTe–AgSbTe2 system to exhibit superior thermoelectric figure of merit (ZT) compared its parent compound SnTe. show AgSbTe2 alloying has a profound impact band structure SnTe by converging energies light and heavy valence bands, leading significantly enhanced Seebeck coefficients. have also unraveled significant connection between defect stability in this system, wherein Sn vacancy concentration increases when Ag Sb are alloyed site. The...
A high ZT (thermoelectric figure of merit) ≈1.4 at 900 K for n‐type PbTe is reported, through modifying its electrical and thermal properties by incorporating Sb S, respectively. confirmed to be an amphoteric dopant in PbTe, filling Te vacancies low doping levels (<1%), exceeding which it enters into Pb sites. It found that Sb‐doped exhibits much higher carrier mobility than similar Bi‐doped materials, accordingly, delivers power factors superior . The enhanced electronic transport...
The off-centered Ge leads to the ultralow lattice thermal conductivity and record high average <italic>ZT</italic> for n-type PbSe.
Abstract High ZT of 1.34 at 766 K and a record high average above 1 in the temperature range 300‐864 are attained n‐type PbTe by engineering temperature‐dependent carrier concentration weakening electron–phonon coupling upon Ga doping. The experimental studies first principles band structure calculations show that doping with introduces shallow level impurity contributing extrinsic carriers imparts deeper ionizes higher temperatures. This adjusts closer to optimum thus maximizes power factor...
We show an example of hierarchically designing electronic bands PbSe toward excellent thermoelectric performance. find that alloying 15 mol % PbTe into causes a negligible change in the light and heavy valence band energy offsets (Δ EV) around room temperature; however, with rising temperature it makes Δ EV decrease at significantly higher rate than PbSe. In other words, temperature-induced convergence is accelerated by PbTe. On this basis, applying 3 Cd substitution on Pb sites...
Abstract Sb‐doped and GeTe‐alloyed n‐type thermoelectric materials that show an excellent figure of merit ZT in the intermediate temperature range (400–800 K) are reported. The synergistic effect favorable changes to band structure resulting high Seebeck coefficient enhanced phonon scattering by point defects nanoscale precipitates reduction thermal conductivity demonstrated. samples can be tuned as single‐phase solid solution (SS) or two‐phase system with (Nano) based on annealing...
Doping Cu<sub>2</sub>Se with Sn enhances the thermoelectric figure of merit and decreases material degradation in power generation conditions.
Thermoelectric generators can convert heat directly into usable electric power but suffer from low efficiencies and high costs, which have hindered wide-scale applications. Accordingly, an important goal in the field of thermoelectricity is to develop new performance materials that are composed more earth-abundant elements. The best systems for midtemperature generation rely on heavily doped PbTe, Te these scarce Earth's crust. PbSe emerging as a less expensive alternative although it...
PbTe-based thermoelectric materials are some of the most promising for converting heat into electricity, but their n-type versions still lag in performance p-type ones. Here, we introduce midgap states and nanoscale precipitates using Ga-doping GeTe-alloying to considerably improve PbTe. The GeTe alloying significantly enlarges energy band gap PbTe subsequent Ga doping introduces special that lead an increased density (DOS) effective mass enhanced Seebeck coefficients. Moreover, nucleated...
We report that Ga-doped and Ga-In-codoped n-type PbS samples show excellent thermoelectric performance in the intermediate temperature range. First-principles electronic structure calculations reveal Ga doping can cause Fermi level pinning by introducing a gap state between conduction valence bands. Furthermore, Ga-In codoping introduces an extra band. These added features lead to high electron mobilities up μH ∼ 630 cm2 V-1 s-1 for n of 1.67 × 1019 cm-3 significantly enhanced Seebeck...
We report the observation of an anomalous nonlinear optical response prototypical three-dimensional topological insulator bismuth selenide through process high-order harmonic generation. find that generation efficiency increases as laser polarization is changed from linear to elliptical, and it becomes maximum for circular polarization. With aid a microscopic theory detailed analysis measured spectra, we reveal such enhancement encodes characteristic topology band structure originates...
Off-centering and core–shell nanoscale CdSe precipitates lead to high thermoelectric performance for p-type, Te-free PbSe systems.
Addressing the irregular electrical conductivity in PbQ–NaSbQ<sub>2</sub> thermoelectrics. Increasing NaSbSe<sub>2</sub> fraction weakens charge carrier screening and strengthens GB scattering.
Owing to the diversity of composition and excellent transport properties, ternary I–III–VI2 type diamond-like chalcopyrite compounds are attractive functional semiconductors, including as thermoelectric materials. In this family, CuInTe2 CuGaTe2 well investigated achieve maximum ZT values ∼1.4 at 950 K an average 0.43. However, both have poor electrical conductivity low temperature, resulting in below 450 K. work, we greatly improved performance quinary diamondoid compound...
Converting waste heat into useful electricity using solid-state thermoelectrics has a potential for enormous global energy savings. Lead chalcogenides are among the most prominent thermoelectric materials, whose performance decreases with an increase in chalcogen amounts (e.g., PbTe > PbSe PbS). Herein, we demonstrate simultaneous optimization of electrical and thermal transport properties PbS-based compounds by alloying GeS. The addition GeS triggers complex cascade beneficial events as...
Here we report that CdTe alloying and Sb doping increase the density-of-states effective mass introduce endotaxial nanostructuring in n-type PbTe, resulting enhanced thermoelectric performance. A prior theoretical prediction for presence of resonance states conduction band this system, however, could not be confirmed. An amount 3 mol % widens gap PbTe by 50%, leading to carrier Seebeck coefficient. This effect is even more pronounced at high temperatures where solubility increases. At 800 K,...
Ag induced phonon–phonon coupling effect leads to ultralow thermal conductivity and high thermoelectric performance of diamond-like material Cu<sub>1−x</sub>Ag<sub>x</sub>InTe<sub>2</sub>.
Abstract Despite the same crystal structure and homologous constituent elements, chalcopyrite compounds ABTe 2 (A = Cu, Ag; B Ga, In) exhibit distinct electronic thermal transport properties. The aim of this work is to understand origin such discrepancy employing experiments theoretical calculations. results Hall coefficient measurements, absorption spectroscopy, studies suggest deep‐level in‐gap states induced by native A‐site vacancies play a key role in observed intrinsic semiconductor...
Defect chemistry is critical to designing high performance thermoelectric materials. In SnTe, the naturally large density of cation vacancies results in excessive hole doping and frustrates ability control properties. Yet, recent work also associates with suppressed sound velocities low lattice thermal conductivity, underscoring need understand interplay between alloying, vacancies, transport properties SnTe. Here, we report solid solutions SnTe NaSbTe2 NaBiTe2 (NaSnmSbTem+2 NaSnmBiTem+2,...
Understanding the nature of phonon transport in solids and underlying mechanism linking lattice dynamics thermal conductivity is important many fields, including development efficient thermoelectric materials where a low required. Herein, we choose pair synthetic chalcopyrite CuFeS2 talnakhite Cu17.6Fe17.6S32 compounds, which possess same elements very similar crystal structures but different transport, as contrasting examples to study influence chemical bonding on properties. Chemically,...
Abstract PbSe is an attractive thermoelectric material due to its favorable electronic structure, high melting point, and lower cost compared PbTe. Herein, the hitherto unexplored alloys of with NaSbSe 2 (NaPb m SbSe +2 ) are described most promising p‐type PbSe‐based thermoelectrics found among them. Surprisingly, it observed that below 500 K, NaPb exhibits unorthodox semiconducting‐like electrical conductivity, despite possessing degenerate carrier densities ≈10 20 cm −3 . It shown...
The entanglement of lattice thermal conductivity, electrical and Seebeck coefficient complicates the process optimizing thermoelectric performance in most materials. Semiconductors with ultralow conductivities high power factors at same time are scarce but fundamentally interesting practically important for energy conversion. Herein, an intrinsic p-type semiconductor TlCuSe that has intrinsically conductivity (0.25 W m-1 K-1 ), a factor (11.6 µW cm-1 K-2 figure merit, ZT (1.9) 643 K is...