Band structure engineering in highly degenerate tetrahedrites through isovalent doping

2016 ◽  
Vol 4 (43) ◽  
pp. 17096-17103 ◽  
Author(s):  
Xu Lu ◽  
Wei Yao ◽  
Guiwen Wang ◽  
Xiaoyuan Zhou ◽  
Donald Morelli ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Band Structure ◽  
Carrier Concentration ◽  
Power Factor ◽  
High Carrier Concentration ◽  
Thermoelectric Power Factor ◽  
Degenerate Semiconductors ◽  
Isovalent Doping ◽  
High Carrier ◽  
Structure Engineering

It can be difficult to reduce the electrical resistivity of highly degenerate semiconductors due to their high carrier concentration, impeding the further increase in their thermoelectric power factor.

Near Band Gap Photoluminescence Broadening In n-Gan Films

1997 ◽  
Vol 482 ◽  
Author(s):  
E. Iliopoulos ◽  
D. Doppalapudi ◽  
H. M. Ng ◽  
T. D. Moustakas
Keyword(s):  
Band Gap ◽  
Carrier Concentration ◽  
Impurity Band ◽  
Potential Method ◽  
Band Broadening ◽  
High Carrier Concentration ◽  
Degenerate Semiconductors ◽  
Compensation Ratio ◽  
High Carrier ◽  
Photoluminescence Peak

AbstractThis paper addresses the broadening mechanism of the near band gap photoluminescence in GaN films doped n-type with silicon. The films were produced by plasma assisted MBE and their carrier concentration was varied systematically from 1015 to 1020 cm−3. The photoluminescence was excited with a 10 mW He-Cd laser at 77K. At low carrier conentration ( < 1017 cm−3 ) the photoluminescence peak has FWHM of about 18 meV, while at high carrier concentration (>1018 cm−3 ) the FWHM increase monotonically with the carrier concentration up to about 120 meV. The broadening of the line at high carrier concentration is attributed to impurity band broadening and tailing of the density of states. The data were quantitatively analyzed, as a function of carrier concentration and compensation ratio, using the impurity band broadening model of Morgan [1] and the agreement between model and experimental data supports the model's validity and suggest a potential method of determining the compensation in degenerate semiconductors.

scholarly journals Band structure engineering through orbital interaction for enhanced thermoelectric power factor

2014 ◽  
Vol 104 (8) ◽  
pp. 082107 ◽  
Author(s):  
Hong Zhu ◽  
Wenhao Sun ◽  
Rickard Armiento ◽  
Predrag Lazic ◽  
Gerbrand Ceder
Keyword(s):  
Band Structure ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Orbital Interaction ◽  
Thermoelectric Power Factor ◽  
Structure Engineering

Band structure engineering of multiple band degeneracy for enhanced thermoelectric power factors in MTe and MSe (M = Pb, Sn, Ge)

RSC Advances ◽  
2015 ◽  
Vol 5 (112) ◽  
pp. 91974-91978 ◽  
Author(s):  
Guangqian Ding ◽  
Jie Li ◽  
Guoying Gao
Keyword(s):  
Band Structure ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Thermoelectric Power Factor ◽  
Multiple Band ◽  
Structure Engineering

The thermoelectric power factor (PF) can be improved by the band structure engineering of multiple band degeneracy.

Synergistic optimization of carrier transport and thermal conductivity in Sn-doped Cu2Te

2018 ◽  
Vol 6 (39) ◽  
pp. 18928-18937 ◽  
Author(s):  
Yuchong Qiu ◽  
Ying Liu ◽  
Jinwen Ye ◽  
Jun Li ◽  
Lixian Lian
Keyword(s):  
Thermal Conductivity ◽  
Fermi Level ◽  
Carrier Concentration ◽  
Power Factor ◽  
Carrier Transport ◽  
Lone Pair ◽  
Thermoelectric Performance ◽  
Degenerate Semiconductors ◽  
Lone Pair Electrons

Doping Sn into the Cu2Te lattice can synergistically enhance the power factor and decrease thermal conductivity, leading to remarkably optimized zTs. The lone pair electrons from the 5s orbital of Sn can increase the DOS near the Fermi level of Cu2Te to promote PF and reduce κe by decreasing the carrier concentration. This study explores a scalable strategy to optimize the thermoelectric performance for intrinsically highly degenerate semiconductors.

Effect of ITO Carrier Concentration on the Performance of Organic Light-Emitting Diodes

1999 ◽  
Vol 598 ◽  
Author(s):  
Furong Zhu ◽  
Keran Zhang ◽  
C. H. A. Huan ◽  
A.T.S. Wee ◽  
Ewald Guenther ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Indium Tin Oxide ◽  
Film Deposition ◽  
Hole Injection ◽  
Maximum Efficiency ◽  
High Carrier Concentration ◽  
Band Bending ◽  
Light Emitting ◽  
Organic Light ◽  
High Carrier

ABSTRACTThe indium tin oxide (ITO) anodes for organic light emitting diode (OLED) were made from an oxidised target with In2O3 and SnO2 in a weight proportion of 9:1 using the RF magnetron sputtering method. The comparable ITO anodes with different carrier concentrations were prepared by varying the hydrogen partial pressure during film deposition. The current-luminance-voltage characteristics of the devices indicated that a high carrier concentration in ITO plays a role in improving OLED performance. A maximum efficiency of 3.8 cd/A was achieved when an ITO anode with a higher carrier concentration of 9×1020 cm−3 was used in a fluorene based OLED. This efficiency is about 1.5 times higher than that of an identical device made with an ITO anode having a lower carrier concentration of 5×1020 cm−3. The increase in electroluminescent efficie ncy reflects an enhanced hole-injection in the device. We consider that enhanced hole injection is due to the reduced band bending in ITO when it has a high carrier concentration

scholarly journals Synergistic boost of output power density and efficiency in In-Li–codoped SnTe

2019 ◽  
Vol 116 (44) ◽  
pp. 21998-22003 ◽  
Author(s):  
Fengkai Guo ◽  
Haijun Wu ◽  
Jianbo Zhu ◽  
Honghao Yao ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Power Density ◽  
Output Power ◽  
Traditional Method ◽  
Lattice Thermal Conductivity ◽  
Heat Output ◽  
Leg Length ◽  
Temperature Dependent ◽  
High Carrier Concentration ◽  
High Carrier

We report enhanced thermoelectric performance of SnTe by further increasing its intrinsic high carrier concentration caused by Sn vacancies in contrast to the traditional method. Along with In2Te3 alloying, which results in an enhanced Seebeck coefficient, Li2Te is added to further increase the carrier concentration in order to maintain high electrical conductivity. Finally, a relatively high PFave of ∼28 μW cm−1 K−2 in the range between 300 and 873 K is obtained in an optimized SnTe-based compound. Furthermore, nanoprecipitates with extremely high density are constructed to scatter phonons strongly, resulting in an ultralow lattice thermal conductivity of ∼0.45 W m−1 K−1 at 873 K. Given that the Z value is temperature dependent, the (ZT)eng and (PF)eng values are adopted to accurately predict the performance of this material. Taking into account the Joule and Thomson heat, output power density of ∼5.53 W cm−2 and leg efficiency of ∼9.6% are calculated for (SnTe)2.94(In2Te3)0.02-(Li2Te)0.045 with a leg length of 4 mm and cold- and hot-side temperatures of 300 and 870 K, respectively.

scholarly journals Low-Resistivity p-Type Doping in Wurtzite ZnS Using Codoping Method

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Deng-Feng Li ◽  
Min Luo ◽  
Bo-Lin Li ◽  
Cheng-Bing Wu ◽  
Bo Deng ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
First Principles ◽  
Ionization Energy ◽  
Formation Energy ◽  
First Principles Calculations ◽  
High Carrier Concentration ◽  
Low Resistivity ◽  
High Carrier ◽  
P Type ◽  
Codoping Method

By using first principles calculations, we propose a codoping method of using acceptors and donors simultaneously to realize low-resistivity and high carrier concentration p-type ZnS with wurtzite structure. The ionization energy of singleNScan be lowered by introducing theIIIZn-NS(III = Al, Ga, In) passivation system. Codoping method in ZnS (2N, III) has lower formation energy comparing with single doping of N since III elements act as reactive codopants.

Sign in / Sign up

Export Citation Format

Share Document