Defects controlled doping and electrical transport in TiS2 single crystals

2020 ◽  
Vol 116 (12) ◽  
pp. 121901
Author(s):  
Ke Chen ◽  
Meng Song ◽  
Yi-Yang Sun ◽  
Hai Xu ◽  
Dong-Chen Qi ◽  
...  
Keyword(s):  
Single Crystals ◽  
Electrical Transport ◽  
Controlled Doping

A study on the effects of mixed organic cations on the structure and properties in lead halide perovskites

2020 ◽  
Vol 22 (5) ◽  
pp. 3105-3111 ◽  
Author(s):  
Chao Wu ◽  
Daoyou Guo ◽  
Peigang Li ◽  
Shunli Wang ◽  
Aiping Liu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Single Crystals ◽  
Electrical Transport ◽  
Organic Cation ◽  
Organic Cations ◽  
Structure And Properties ◽  
Electrical Transport Properties ◽  
Halide Perovskites ◽  
A Site ◽  
Lead Halide

Four types of organic cation-mixed single crystals were successfully synthesized by partially substituting A site cations to investigate the effect of organic cations on structure, optical features, thermal stability, and electrical transport properties.

Synthesis and electrical transport properties of Bi2O2Se single crystals

2018 ◽  
Vol 498 ◽  
pp. 244-247 ◽  
Author(s):  
Qianhui Mao ◽  
Xiaodong Geng ◽  
Jinfeng Yang ◽  
Junji Zhang ◽  
Shuangmei Zhu ◽  
...  
Keyword(s):  
Transport Properties ◽  
Single Crystals ◽  
Electrical Transport ◽  
Electrical Transport Properties

Electrical Transport Properties of the Pentatelluride Materials Hfte5 and Zrte5

1997 ◽  
Vol 478 ◽  
Author(s):  
T. M. Tritt ◽  
M. L. Wilson ◽  
R. L. Littleton ◽  
C. Feger ◽  
J. Kolis ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Electrical Transport ◽  
Entire Range ◽  
Room Temperature ◽  
Polycrystalline Material ◽  
Polycrystalline Materials ◽  
Electrical Transport Properties ◽  
Low Dimensional ◽  
P Type

AbstractWe have measured the resistivity and thermopower of single crystals as well as polycrystalline pressed powders of the low-dimensional pentatelluride materials: HfTe5 and ZrTe5. We have performed these measurements as a function of temperature between 5K and 320K. In the single crystals there is a peak in the resistivity for both materials at a peak temperature, Tp where Tp ≈ 80K for HfTe5 and Tp ≈ 145K for ZrTe5. Both materials exhibit a large p-type thermopower around room temperature which undergoes a change to n-type below the peak. This data is similar to behavior observed previously in these materials. We have also synthesized pressed powders of polycrystalline pentatelluride materials, HfTe5 and ZrTe5. We have measured the resistivity and thermopower of these polycrystalline materials as a function of temperature between 5K and 320K. For the polycrystalline material, the room temperature thermopower for each of these materials is relatively high, +95 μV/K and +65 μV/K for HfTe5 and ZrTe5 respectively. These values compare closely to thermopower values for single crystals of these materials. At 77 K, the thermopower is +55 μV/K for HfTe5 and +35 μV/K for ZrTe5. In fact, the thermopower for the polycrystals decreases monotonically with temperature to T ≈ 5K, thus exhibiting p-type behavior over the entire range of temperature. As expected, the resistivity for the polycrystals is higher than the single crystal material, with values of 430 mΩ-cm and 24 mΩ-cm for Hfre5 and ZrTe5 respectively, compared to single crystal values of 0.35 mΩ-cm (HfTe5) and 1.0 mΩ-cm (ZrTe5). We have found that the peak in the resistivity evident in both single crystal materials is absent in these polycrystalline materials. We will discuss these materials in relation to their potential as candidates for thermoelectric applications.

Sol-Gel Silicon Carbide for Photonic Applications

2006 ◽  
Vol 527-529 ◽  
pp. 759-762 ◽  
Author(s):  
B. Friedel ◽  
Siegmund Greulich-Weber
Keyword(s):  
Single Crystals ◽  
Deep Level ◽  
Sol Gel ◽  
Photonic Bandgap Materials ◽  
Sol Gel Process ◽  
Annealing Procedure ◽  
Gel Preparation ◽  
Amorphous Sic ◽  
Porous Sic ◽  
Controlled Doping

We have investigated the growth of SiC, following a modified sol-gel process, which not only allows the realization of 3D photonic bandgap materials but also is useful for various SiC applications like templates in medicine or filters in harsh environment. Depending on the sol-gel annealing procedure one obtains macro-porous SiC, amorphous SiC, or from nano to micrometer-sized 3C-SiC single crystals. At low annealing temperatures preferably nanowires are grown. Via various sol-gel-annealing procedures we are able to prepare single crystals with sizes ranging from several nm up to several 100 %m, while the resulting polytype only depends on the annealing temperature available. Not only for photonic applications useable procedures for doping with shallow level donors and acceptors as well as with deep level defects are essential. We show that controlled doping is possible either during the sol-gel preparation or via the gas phase during the following annealing procedure.

scholarly journals Anderson localization of electrons in single crystals: LixFe7Se8

2016 ◽  
Vol 2 (2) ◽  
pp. e1501283 ◽  
Author(s):  
Tianping Ying ◽  
Yueqiang Gu ◽  
Xiao Chen ◽  
Xinbo Wang ◽  
Shifeng Jin ◽  
...  
Keyword(s):  
Fermi Level ◽  
Single Crystals ◽  
Electrical Transport ◽  
Three Dimensional ◽  
Electronic States ◽  
Coulomb Repulsion ◽  
Experimental Investigations ◽  
Crystalline Materials ◽  
Lattice Disorder ◽  
Anderson Insulators

Anderson (disorder-induced) localization, proposed more than half a century ago, has inspired numerous efforts to explore the absence of wave diffusions in disordered media. However, the proposed disorder-induced metal-insulator transition (MIT), associated with the nonpropagative electron waves, has hardly been observed in three-dimensional (3D) crystalline materials, let alone single crystals. We report the observation of an MIT in centimeter-size single crystals of LixFe7Se8induced by lattice disorder. Both specific heat and infrared reflectance measurements reveal the presence of considerable electronic states in the vicinity of the Fermi level when the MIT occurs, suggesting that the transition is not due to Coulomb repulsion mechanism. The 3D variable range hopping regime evidenced by electrical transport measurements at low temperatures indicates the localized nature of the electronic states on the Fermi level. Quantitative analyses of carrier concentration, carrier mobility, and simulated density of states (DOS) fully support that LixFe7Se8is an Anderson insulator. On the basis of these results, we provide a unified DOS picture to explain all the experimental results, and a schematic diagram for finding other potential Anderson insulators. This material will thus serve as a rich playground for both theoretical and experimental investigations on MITs and disorder-induced phenomena.

Low temperature electrical transport properties of RuO2 and IrO2 single crystals

2004 ◽  
Vol 16 (45) ◽  
pp. 8035-8041 ◽  
Author(s):  
J J Lin ◽  
S M Huang ◽  
Y H Lin ◽  
T C Lee ◽  
H Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Transport Properties ◽  
Single Crystals ◽  
Electrical Transport ◽  
Electrical Transport Properties
Sign in / Sign up

Export Citation Format

Share Document