Layer interdependence of transport in an undoped electron-hole bilayer
Layer interdependence of transport in an undoped electron-hole bilayer
复制标题
未掺杂的电子-空穴双层中传输的层相互依赖性
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
M. Lilly
中科院分区：
文献类型：
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作者：
C. Morath;J. Seamons;J. Reno;M. Lilly
研究了非掺杂电子-空穴双层(UEHBL)器件的输运特性与载流子密度、层间电场和温度的关系。UEHBL器件由密度可调、独立接触的二维电子气(2DEG)和由30 nm Al0.9Ga0.1As势垒隔开的不同的GaAs场效应诱导的二维空穴气体(2DHG)组成。使用范德堡方法在每一层上同时进行了传输测量。2DHG的迁移率随2DEG浓度的增加而增大，而2DEG的迁移率与2DHG浓度的依赖关系不大。减小层间电场从而增加层间距也增加了2DHG的迁移率，而对2DEG迁移率的影响可以忽略不计。利用2DHG库仑阻力测量，估算了层间电场变化对层间分离的影响。结果表明，各层的迁移率仅间接依赖于相邻层的密度，并以背景杂质散射为主。还确定了每一层的电阻率的温度依赖关系。
The layer interdependence of transport in an undoped electron-hole bilayer (uEHBL) device was studied as a function of carrier density, interlayer electric field, and temperature. The uEHBL device consisted of a density tunable, independently contacted two-dimensional electron gas (2DEG) and two-dimensional hole gas (2DHG) induced via field effect in distinct GaAs quantum wells separated by a 30 nm Al$_{0.9}$Ga$_{0.1}$As barrier. Transport measurements were made simultaneously on each layer using the van der Pauw method. An increase in 2DHG mobility with increasing 2DEG density was observed, while the 2DEG mobility showed negligible dependence on the 2DHG density. Decreasing the interlayer electric-field and thereby increasing interlayer separation also increased the 2DHG mobility with negligible effects on the 2DEG mobility. The change in interlayer separation as interlayer electric-field changed was estimated using 2DHG Coulomb drag measurements. The results were consistent with mobility of each layer being only indirectly dependent on the adjacent layer density and dominated by background impurity scattering. Temperature dependencies were also determined for the resistivity of each layer.