Effect of Quantum Effects on Electrical Transport in Si/Ge/Si Sandwich Structure

Thermoelectric microcooling is expected to solve the high heat flux caused by rapidly increasing packaging density of IC chips, for advantages as long lifetime, no moving parts and compatibility with IC fabrication, and etc. However the coefficient of performance of thermoelectric devices is still limited by the low figure of merit. In this paper, we simulated Si/Ge/Si sandwich simplified model, a kind of low dimensional structures which could be used to enhance the figure of merit proposed by Hicks and Dresselhaus [1] firstly, with planar and non-planar interfaces to investigate the characteristic of carriers' transport, by using modified two-dimensional simulator Archimedes (GNU package) based on Mento Carlo method. The results show that for structure of nano scale, quantum effects, especially quantum tunneling, will greatly affect the Seebeck coefficient, resulting in lower thermoelectric figure of merit, even though electrical conductivity increases.