Seebeck coefficient characterization of highly doped n- and p-type silicon nanowires for thermoelectric device applications fabricated with top-down approach.

ABSTRACT

A silicon nanowire one-dimensional thermoelectric device is presented as a solution to enhance thermoelectric performance. A top-down process is adopted for the definition of 50 nm silicon nanowires (SiNWs) and the fabrication of the nano-structured thermoelectric devices on silicon on insulator (SOl) wafer. To measure the Seebeck coefficients of 50 nm width n- and p-type SiNWs, a thermoelectric test structure, containing SiNWs, micro-heaters and temperature sensors is fabricated. Doping concentration is 1.0 x 10(20) cm(-3) for both for n- and p-type SiNWs. To determine the temperature gradient, a temperature coefficient of resistance (TCR) analysis is done and the extracted TCR value is 1750-1800 PPM x K(-1). The measured Seebeck coefficients are -127.583 microV x K(-1) and 141.758 microV x K(-1) for n- and p-type SiNWs, respectively, at room temperature. Consequently, power factor values are 1.46 mW x m(-1) x K(-2) and 1.66 mW x m(-1) x K(-2) for n- and p-type SiNWs, respectively. Our results indicate that SiNWs based thermoelectric devices have a great potential for applications in future energy conversion systems.