2D planar penta-MN2 (M = Pd, Pt) sheets identified through structure search

2019 ◽  
Vol 21 (1) ◽  
pp. 246-251 ◽  
Author(s):  
Kexian Zhao ◽  
Xiaoyin Li ◽  
Shuo Wang ◽  
Qian Wang
Keyword(s):  
Carrier Mobility ◽  
Structure Search ◽  
Higher Carrier Mobility

Planar penta-MN2 sheets are energetically more stable than pyrite MN2, and penta-PtN2 has higher carrier mobility than phosphorene.

scholarly journals Backbone Effects on the Thermoelectric Properties of Ultra-Small Bandgap Conjugated Polymers

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2486
Author(s):  
Dexun Xie ◽  
Jing Xiao ◽  
Quanwei Li ◽  
Tongchao Liu ◽  
Jinjia Xu ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Power Factor ◽  
Carrier Mobility ◽  
Polymeric Materials ◽  
Thermoelectric Performance ◽  
Organic Thermoelectric Materials ◽  
Higher Power ◽  
Donor Acceptor ◽  
Maximum Power Factor ◽  
Higher Carrier Mobility

Conjugated polymers with narrower bandgaps usually induce higher carrier mobility, which is vital for the improved thermoelectric performance of polymeric materials. Herein, two indacenodithiophene (IDT) based donor–acceptor (D-A) conjugated polymers (PIDT-BBT and PIDTT-BBT) were designed and synthesized, both of which exhibited low-bandgaps. PIDTT-BBT showed a more planar backbone and carrier mobility that was two orders of magnitude higher (2.74 × 10−2 cm2V−1s−1) than that of PIDT-BBT (4.52 × 10−4 cm2V−1s−1). Both exhibited excellent thermoelectric performance after doping with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, where PIDTT-BBT exhibited a larger conductivity (0.181 S cm−1) and a higher power factor (1.861 μW m−1 K−2) due to its higher carrier mobility. The maximum power factor of PIDTT-BBT reached 4.04 μW m−1 K−2 at 382 K. It is believed that conjugated polymers with a low bandgap are promising in the field of organic thermoelectric materials.

Electrical conductivity and Einstein relation modeling in phosphorene

2019 ◽  
Vol 33 (06) ◽  
pp. 1950033
Author(s):  
E. Mansouri ◽  
J. Karamdel ◽  
M. T. Ahmadi ◽  
M. Berahman
Keyword(s):  
Diffusion Coefficient ◽  
Fermi Energy ◽  
Carrier Mobility ◽  
2D Materials ◽  
Einstein Relation ◽  
Fundamental Parameters ◽  
Electron Diffusion Coefficient ◽  
Energy Formula ◽  
Higher Carrier Mobility ◽  
And Diffusion

Investigation on (2-dimensional) (2D) materials is growing significantly due to the fundamental electronic properties in the direct inherent bandgap, higher carrier mobility, and easier exfoliation. Phosphorene as a new 2D configuration has presented excellent potential in electronic and optoelectronic applications. In this study, the conductivity of monolayer phosphorene and Einstein’s relations as fundamental parameters in semiconductor manufacturing are analytically modeled. In addition, dependency of conductivity on normalized Fermi energy ([Formula: see text]) is demonstrated. According to the simulation results, conductivity and Einstein’s relation are completely dependent on temperature, therefore, rising up the temperature leads to conductivity and diffusion coefficient (Dn) growth. Indeed, conductivity is saturated when the normalized Fermi energy exceeds than 6. Also, the conductivity and Einstein’s relation dependency to voltage are studied. Results show that carrier conductivity and the electron diffusion coefficient (Dn) increase by amplifying the voltage.

scholarly journals Gated Graphene Electrical Transport Characterization

10.14311/1644 ◽  
2012 ◽  
Vol 52 (5) ◽  
Author(s):  
Josef Náhlík ◽  
Michal Janoušek ◽  
Zbyněk Šobáň
Keyword(s):  
Gate Voltage ◽  
Electrical Transport ◽  
Carrier Mobility ◽  
Room Temperature ◽  
Transparent Material ◽  
Carbon Structure ◽  
Physical Behavior ◽  
Sweep Direction ◽  
New Material ◽  
Higher Carrier Mobility

Graphene is a very interesting new material, and promises attractive applications in future nanodevices. It is a 2D carbon structure with very interesting physical behavior. Graphene is an almost transparent material that has higher carrier mobility than any other material at room temperature. Graphene can therefore be used in applications such as ultrahigh-speed transistors and transparent electrodes. In this paper, we present our preliminary experiments on the transport behavior of graphene at room temperature. We measured the resistivity of Hall-bar samples depending on gate voltage (backgated graphene). Hysteresis between the forward and backward sweep direction was observed.

scholarly journals Structure and Doping Optimization of IDT-Based Copolymers for Thermoelectrics

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1463
Author(s):  
Tongchao Liu ◽  
Dexun Xie ◽  
Jinjia Xu ◽  
Chengjun Pan
Keyword(s):  
Organic Semiconductors ◽  
Carrier Mobility ◽  
Carrier Transport ◽  
Room Temperature ◽  
Charge Carrier Transport ◽  
Structure Property ◽  
Polymer Backbone ◽  
Donor Acceptor ◽  
Higher Carrier Mobility ◽  
The Relationship

π-conjugated backbones play a fundamental role in determining the thermoelectric (TE) properties of organic semiconductors. Understanding the relationship between the structure–property–function can help us screen valuable materials. In this study, we designed and synthesized a series of conjugated copolymers (P1, P2, and P3) based on an indacenodithiophene (IDT) building block. A copolymer (P3) with an alternating donor–acceptor (D-A) structure exhibits a narrower band gap and higher carrier mobility, which may be due to the D-A structure that helps reduce the charge carrier transport obstacles. In the end, its power factor reaches 4.91 μW m−1 K−2 at room temperature after doping, which is superior to those of non-D-A IDT-based copolymers (P1 and P2). These results indicate that moderate adjustment of the polymer backbone is an effective way to improve the TE properties of copolymers.

scholarly journals Physical Properties of Sputtered Germanium-Doped Indium Tin Oxide Films (ITO: Ge) Obtained at Low Deposition Temperature

1993 ◽  
Vol 15 (2) ◽  
pp. 67-74
Author(s):  
S. J. Wen ◽  
G. Campet ◽  
J. P. Manaud
Keyword(s):  
Low Temperature ◽  
Physical Properties ◽  
Tin Oxide ◽  
Relative Position ◽  
Indium Tin Oxide ◽  
Deposition Temperature ◽  
Carrier Mobility ◽  
Higher Carrier Mobility ◽  
Tin Oxide Films ◽  
Low Deposition Temperature

Undoped and Ge-doped ITO films (ITO: Ge) deposited at low temperature (70℃) have been studied. Although both samples have the same carrier concentration, a higher carrier mobility occurs for ITO: Ge. An evaluation of the relative position of the dopant associated energy states has been carried out.

scholarly journals Two-Dimensional TeB Structures with Anisotropic Carrier Mobility and Tunable Bandgap

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6404
Author(s):  
Yukai Zhang ◽  
Xin Qu ◽  
Lihua Yang ◽  
Xin Zhong ◽  
Dandan Wang ◽  
...  
Keyword(s):  
Carrier Mobility ◽  
Density Functional ◽  
Hole Mobility ◽  
Two Dimensional ◽  
Thermal Stabilities ◽  
2D Semiconductors ◽  
Structure Search ◽  
Direct Band ◽  
High Carrier Mobility ◽  
Bandgap Semiconductors

Two-dimensional (2D) semiconductors with desirable bandgaps and high carrier mobility have great potential in electronic and optoelectronic applications. In this work, we proposed α-TeB and β-TeB monolayers using density functional theory (DFT) combined with the particle swarm-intelligent global structure search method. The high dynamical and thermal stabilities of two TeB structures indicate high feasibility for experimental synthesis. The electronic structure calculations show that the two structures are indirect bandgap semiconductors with bandgaps of 2.3 and 2.1 eV, respectively. The hole mobility of the β-TeB sheet is up to 6.90 × 102 cm2 V−1 s−1. By reconstructing the two structures, we identified two new horizontal and lateral heterostructures, and the lateral heterostructure presents a direct band gap, indicating more probable applications could be further explored for TeB sheets.

scholarly journals Manipulation of ionized impurity scattering for achieving high thermoelectric performance in n-type Mg3Sb2-based materials

2017 ◽  
Vol 114 (40) ◽  
pp. 10548-10553 ◽  
Author(s):  
Jun Mao ◽  
Jing Shuai ◽  
Shaowei Song ◽  
Yixuan Wu ◽  
Rebecca Dally ◽  
...  
Keyword(s):  
Power Factor ◽  
Carrier Mobility ◽  
Phonon Scattering ◽  
Impurity Scattering ◽  
Substantial Improvement ◽  
Thermoelectric Performance ◽  
Scattering Mechanism ◽  
Carrier Scattering ◽  
Ionized Impurity Scattering ◽  
Higher Carrier Mobility

Achieving higher carrier mobility plays a pivotal role for obtaining potentially high thermoelectric performance. In principle, the carrier mobility is governed by the band structure as well as by the carrier scattering mechanism. Here, we demonstrate that by manipulating the carrier scattering mechanism in n-type Mg3Sb2-based materials, a substantial improvement in carrier mobility, and hence the power factor, can be achieved. In this work, Fe, Co, Hf, and Ta are doped on the Mg site of Mg3.2Sb1.5Bi0.49Te0.01, where the ionized impurity scattering crosses over to mixed ionized impurity and acoustic phonon scattering. A significant improvement in Hall mobility from ∼16 to ∼81 cm2⋅V−1⋅s−1 is obtained, thus leading to a notably enhanced power factor of ∼13 μW⋅cm−1⋅K−2 from ∼5 μW⋅cm−1⋅K−2. A simultaneous reduction in thermal conductivity is also achieved. Collectively, a figure of merit (ZT) of ∼1.7 is obtained at 773 K in Mg3.1Co0.1Sb1.5Bi0.49Te0.01. The concept of manipulating the carrier scattering mechanism to improve the mobility should also be applicable to other material systems.

Effects of Substrate Temperature on the Properties of Cu(In,Ga)Se2 Thin Films Prepared by Sputtering from a Quaternary Target

2014 ◽  
Vol 1061-1062 ◽  
pp. 209-214 ◽  
Author(s):  
Zi Yue Yang ◽  
Li Dong Wang ◽  
Rui Xuan Song ◽  
Dong Xing Zhang ◽  
Wei Dong Fei
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Carrier Mobility ◽  
Hall Effect Measurement ◽  
Chalcopyrite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Electrical Properties ◽  
Higher Carrier Mobility ◽  
Substrate Temperatures

Cu (In,Ga)Se2(CIGS) thin films were prepared by direct magnetron sputtering CIGS quaternary target at the substrate temperature varying from room temperature (RT) to 300 °C. The effects of substrate temperature on the structural and electrical properties of CIGS films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and Hall effect measurement. The CIGS thin films with a chalcopyrite structure were obtained between 100 and 300 °C and the crystallinity of films were enhanced with the increase of the substrate temperature from 100 to 300 °C. The film compositions were consisted with the target when the substrate temperatures were between RT and 200 °C, however, it deviated from the stoichiometry of the target when the substrate temperature was 300 °C. The CIGS films deposited at 200 °C had the higher carrier mobility of 3.522 cm2/Vs.

Strain: A Solution for Higher Carrier Mobility in Nanoscale MOSFETs

2009 ◽  
Vol 39 (1) ◽  
pp. 203-229 ◽  
Author(s):  
Min Chu ◽  
Yongke Sun ◽  
Umamaheswari Aghoram ◽  
Scott E. Thompson
Keyword(s):  
Carrier Mobility ◽  
Nanoscale Mosfets ◽  
Higher Carrier Mobility
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