Peltier effect in doped silicon microchannel plates

The Seebeck coefficient is determined from silicon microchannel plates (Si MCPs) prepared by photo-assisted electrochemical etching at room temperature (25 °C). The coefficient of the sample with a pore size of 5 × 5 μm2, spacing of 1 μm and thickness of about 150 μm is −852 μV/K along the edge of the square pore. After doping with boron and phosphorus, the Seebeck coefficient diminishes to 256 μV/K and −117 μV/K along the edge of the square pore, whereas the electrical resistivity values are 7.5 × 10−3 Ω·cm and 1.9 × 10−3 Ω·cm, respectively. Our data imply that the Seebeck coefficient of the Si MCPs is related to the electrical resistivity and is consistent with that of bulk silicon. Based on the boron and phosphorus doped samples, a simple device is fabricated to connect the two type Si MCPs to evaluate the Peltier effect. When a proper current passes through the device, the Peltier effect is evidently observed. Based on the experimental data and the theoretical calculation, the estimated intrinsic figure of merit ZT of the unicouple device and thermal conductivity of the Si MCPs are 0.007 and 50 W/(m·K), respectively.