Anisotropy of mobility ratio between electron and hole along different orientations in ReGexSi1.75-x thermoelectric single crystals
Anisotropy of mobility ratio between electron and hole along different orientations in ReGexSi1.75-x thermoelectric single crystals
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DOI：
10.1103/physrevb.71.113201
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发表时间：
2005-03
影响因子：
3.7
通讯作者：
Jiajun Gu;M. Oh;H. Inui;Di Zhang
中科院分区：
文献类型：
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作者：
Jiajun Gu;M. Oh;H. Inui;Di Zhang
最近发现，ReSi{sub 1.75}基半导体单晶可以是具有固定组成的p型或n型，这仅仅取决于它们不同的晶体取向。为了研究这一有趣现象的机理，我们用辐射加热浮区法生长了ReGe{sub x}Si{sub 1.75-x}（x=0.02和0.04）单晶。分别沿[100]和[001]沿着测量这些样品的塞贝克系数和电阻率。在50 ~ 800 ℃温度范围内，沿[100]方向的导电机制为p型，沿着[001]方向的导电机制为n型，类似于二元ReSi{sub 1.75}。C.从Seebeck系数数据计算出电子和空穴之间的迁移率比，并且它沿着两个不同的取向是高度各向异性的（沿着[100]方向约为0.4至0.6，沿着[001]方向约为4至5），从而引起在ReSi{sub 1.75}中观察到的取向相关的导电符号反转现象。
It was recently found that ReSi{sub 1.75} based semiconductor single crystals can be of either p or n type with a fixed composition, just depending on their different crystal orientations. To investigate the mechanism of this interesting phenomenon, we grow ReGe{sub x}Si{sub 1.75-x} (x=0.02 and 0.04) single crystals with a floating zone method with radiation heating. The Seebeck coefficient and electric resistivity of these samples are measured along [100] and [001], respectively. The conduction mechanism is of p type along [100] and of n type along [001], like binary ReSi{sub 1.75}, in the temperature range 50 to 800 deg. C. The mobility ratio between electron and hole is calculated from the Seebeck coefficient data and it is highly anisotropic along two different orientations (about 0.4 to 0.6 along [100] while 4 to 5 along [001] direction), giving rise to the orientation-dependent conduction sign reversal phenomenon observed in ReSi{sub 1.75}.