Silicon nanowire based thermoelectric device for energy harvesting

We investigate the effect of diameter and doping condition on thermal conductivity of vertical nanowires. Vertical silicon nanowire array/spin-on glass (SOG) composite films were fabricated using CMOS technology to extract thermal conductivity of vertical nanowire. The thermal conductivity is reduced by about 27% when diameter is decreased from 350 nm to 190 nm. In addition, boron doped and phosphorus doped nanowires exhibit thermal conductivity of 14.54 Wm^-1·K^-1 and 17.15 Wm^-1·K^-1, respectively. Doping method can reduce thermal conductivity of vertical nanowire by up to 70%. Consequently, silicon based thermoelectric devices with highly doped p-type and n-type nanowires were fabricated uniformly. The fabricated devices can be used as a promising thermoelectric power generation and show a Seebeck voltage of 15 mV.