Surface Disordered Ge–Si Core–Shell Nanowires as Efficient Thermoelectric Materials

Nano Letters ◽  
2012 ◽  
Vol 12 (9) ◽  
pp. 4698-4704 ◽  
Author(s):  
Troels Markussen
2005 ◽  
Vol 886 ◽  
Author(s):  
Ming Y. Tang ◽  
Mildred S. Dresselhaus ◽  
Ronggui Yang ◽  
Gang Chen

ABSTRACTThermoelectrics have always been attractive for power generation and cooling because of power reliability and environmentally friendly issues. However, this concept remains non-competitive due to the limitation in the efficiency of available thermoelectric materials and device designs [1]. In the 1990s, Hicks and Dresselhaus predicted the possibility of a dramatic enhancement in thermoelectric performance based on the special behavior of low dimensional materials [2, 3]. This enhancement is in part due to the increase in quantum confinement effects, the increase in electronic density of states at specified energies, and the increase in the phonon interface scattering for low dimensional structures.Nanowires and core-shell nanowires can be considered to be model systems to illustrate representative behavior in low dimensional thermoelectric materials. It is expected that a system made out of nanowires or core-shell nanowires would have a higher thermoelectric performance than its bulk counterpart due to an increase in the number of interfaces. The interfaces that are introduced must be such that phonons are scattered more strongly than are electrons. Theoretical studies have been carried out to better understand the transport properties of Si-Si1−xGex ordered nanowire composites. The composite is modeled as having Si wires embedded in a Si1−xGex host matrix. Thus, core-shell Si/Si1−xGex nanowires can be considered as a building block of the composite. The effect of the wire diameter and the shell alloy composition on ZT is presented.


2019 ◽  
Author(s):  
Jiajia Tao ◽  
Hong-Ping Ma ◽  
Kaiping Yuan ◽  
Yang Gu ◽  
Jianwei Lian ◽  
...  

<div>As a promising oxygen evolution reaction semiconductor, TiO2 has been extensively investigated for solar photoelectrochemical water splitting. Here, a highly efficient and stable strategy for rationally preparing GaON cocatalysts on TiO2 by atomic layer deposition is demonstrated, which we show significantly enhances the</div><div>photoelectrochemical performance compared to TiO2-based photoanodes. For TiO2@20 nm-GaON core-shell nanowires a photocurrent density up to 1.10 mA cm-2 (1.23 V vs RHE) under AM 1.5 G irradiation (100 mW cm-2) has been achieved, which is 14 times higher than that of TiO2 NWs. Furthermore, the oxygen vacancy formation on GaON as well as the band gap matching with TiO2 not only provides more active sites for water oxidation but also enhances light absorption to promote interfacial charge separation and migration. Density functional theory studies of model systems of GaON-modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaON core-shell nanowires provide a deeper understanding and universal strategy for enhancing photoelectrochemical performance of photoanodes now available. </div>


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Jaemin Park ◽  
Sucheol Ju ◽  
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...  

2019 ◽  
Vol 30 (30) ◽  
pp. 304001 ◽  
Author(s):  
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G Patriarche ◽  
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...  
Keyword(s):  

Nano Research ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 61-66
Author(s):  
Alexandre Bucamp ◽  
Christophe Coinon ◽  
David Troadec ◽  
Sylvie Lepilliet ◽  
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...  

AIP Advances ◽  
2013 ◽  
Vol 3 (6) ◽  
pp. 062114 ◽  
Author(s):  
P. Sangeetha ◽  
K. Jeganathan ◽  
V. Ramakrishnan
Keyword(s):  

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