Characterization of nanometer-thick polycrystalline silicon with phonon-boundary scattering enhanced thermoelectric properties and its application in infrared sensors†

摘要: Although significantly reducing the thermal conductivity of silicon nanowires has been reported, it remains a challenge to integrate with structure materials and electrodes in complementary metal–oxide–semiconductor (CMOS) process. In this paper, we investigated nanometer-thick polycrystalline (poly-Si) theoretically experimentally. By leveraging phonon-boundary scattering, 52 nm thick poly-Si was measured as low around 12 W mK−1 which is only about 10% value bulk single crystalline silicon. The ZT n-doped p-doped 0.067 0.024, respectively, while most previously reported data had values 0.02 0.01 for layer thickness 0.5 μm above. Thermopile infrared sensors comprising 128 pairs thermocouples made either or strips series connected by an aluminium (Al) metal interconnect are fabricated using microelectromechanical system (MEMS) technology. vacuum specific detectivity (D*) thermopile (IR) 3.00 × 108 1.83 cm Hz1/2 W−1 poly-Si, 5.75 107 3.95 300 respectively. outstanding thermoelectric properties indicate our approach promising diverse applications ultrathin