Transport properties of polycrystalline Si0.8Ge0.2 thin films for micro power generators

The transport properties of polycrystalline Si_0.8Ge_0.2 thin films are studied for their potential applications in micro power generators. These thin films are deposited by low-pressure chemical deposition (LPCVD). The doping is carried out by boron and phosphorus ion implantation, followed by annealing in nitrogen ambient. The concentration of boron and phosphorus 4.3x10¹⁹ cm^-3, and 8.7x10¹⁹ cm^-3, respectively. The thermoelectric transport properties of these thin films are measured, including electrical conductivity, Seebeck coefficient, and thermal conductivity. The electrical conductivity is measured by a 4 point-probe method. The Seebeck coefficient is measured by applying a temperature gradient along the in-plane direction, and evaluating the resulting voltage. The thermal conductivity is measured by a 3ω method in the cross-plane direction.