Theoretical investigation of the effects of doping on the electronic structure and thermoelectric properties of ZnO nanowires.
Theoretical investigation of the effects of doping on the electronic structure and thermoelectric properties of ZnO nanowires.
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DOI：
10.1039/c3cp54289k
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发表时间：
2014-01
期刊：
影响因子：
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通讯作者：
Chao Wang;Yuanxu Wang;Guangbiao Zhang;Chengxiao Peng;Gui Yang
中科院分区：
文献类型：
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作者：
Chao Wang;Yuanxu Wang;Guangbiao Zhang;Chengxiao Peng;Gui Yang
通过第一性原理计算研究了Al、Ga、Sb掺杂对氧化锌纳米线电子结构和热电性能的影响。我们发现Al和Ga掺杂后，氧化锌纳米线的禁带宽度变窄，而掺Sb的氧化锌纳米线的禁带宽度变宽。利用德拜-卡拉韦模型计算了氧化锌纳米线的晶格热导率。用BoltzTraP程序计算了氧化锌纳米线的热电性质。结果表明，在室温下，Al、Ga、Sb掺杂的氧化锌纳米线存在一个最佳的载流子浓度，从而产生最大的ZT。对于Ga掺杂的氧化锌纳米线，当载流子浓度为3.62×10(19)cm(-3)时，ZT达到最大值0.147。在400~1200K温度范围内，掺Sb的氧化锌纳米线的热电性能优于掺镓的氧化锌纳米线，Al掺杂的氧化锌纳米线的热电性能一直较差，这意味着在热电应用中掺铝的氧化锌纳米线可能不是最佳的选择。
The effects of doping ZnO nanowires with Al, Ga and Sb on their electronic structure and thermoelectric properties are investigated by first-principles calculations. We find that the band gap of ZnO nanowires is narrowed after doping with Al and Ga, while band gap broadening is observed in Sb doped ZnO nanowires. The lattice thermal conductivity of ZnO nanowires is obtained based on the Debye-Callaway model. The thermoelectric properties of ZnO nanowires were calculated using the BoltzTraP code. The results show that there exists an optimal carrier concentration yielding the maximum value of ZT for Al, Ga and Sb doped ZnO nanowires at room temperature. The maximum value of ZT, 0.147, is obtained for Ga doped ZnO nanowires, when the carrier concentration is 3.62 × 10(19) cm(-3). The figure of merit ZT of Sb doped ZnO nanowires is higher than that of Ga doped ZnO nanowires when the temperature is between 400 K and 1200 K. We also find that Al doped ZnO nanowires always have poor thermoelectric properties, which means that the Al dopant may not be the optimal choice for ZnO nanowires in thermoelectric applications.