University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Phys Rev Lett. 2010 Dec 17;105(25):256601. doi: 10.1103/PhysRevLett.105.256601. Epub 2010 Dec 13.
We report thermoelectric measurements on a silicon nanoribbon in which an integrated gate provides strong carrier confinement and enables tunability of the carrier density over a wide range. We find a significantly enhanced thermoelectric power factor that can be understood by considering its behavior as a function of carrier density. We identify the underlying mechanisms for the power factor in the nanoribbon, which include quantum confinement, low scattering due to the absence of dopants, and, at low temperatures, a significant phonon-drag contribution. The measurements set a target for what may be achievable in ultrathin nanowires.
我们报告了在硅纳米带中进行的热电测量结果，其中集成栅极提供了强大的载流子限制，并能够在很宽的范围内调节载流子密度。我们发现了显著增强的热电功率因子，通过考虑其作为载流子密度函数的行为，可以理解这一点。我们确定了纳米带中功率因子的基础机制，包括量子限制、由于没有掺杂剂而导致的低散射，以及在低温下，显著的声子拖拽贡献。这些测量结果为在超薄纳米线中可能实现的目标设定了一个基准。
