Anisotropy of Seebeck coefficient in Si/Ge composite quantum dots

作者：Hsin Cheng Lun^*; Tsai Yue Yun; Lee Sheng Wei

来源：Applied Physics Letters, 2016, 109(8): 083901.

DOI：10.1063/1.4961535

In this report, Si5Ge5 alloy and Si/Ge composite quantum dots (CQDs) layers were grown on Si substrates. Seebeck coefficient (S) of Si and Ge wafers, as well as these two samples, were patterned and measured from 60 to 180 degrees C in [110] and [010] directions. For Si, Ge, and Si5Ge5, the S of each is a constant in this temperature range. However, the S of the CQDs at 60-80 degrees C is anomalous and much higher than the others. The behavior of the voltage difference is linear to the temperature difference even as large as 50 degrees C, except for CQDs at 60-80 degrees C. This result indicates that a narrow distribution of carriers energy with a sharp change in density of state near Fermi-level and selective carrier scattering in the miniband at Si/Ge interface make the discrepancy of charge transport enhanced. The CQDs can be a good candidate for temperature sensing and thermoelectric applications due to their high S and low thermal conductivity near room temperature. Published by AIP Publishing.

• 出版日期2016-8-22
• 单位中央民族大学