Thermoelectric behavior of microchannel plates fabricated by photo-assisted electrochemical etching

We demonstrate the favorable thermoelectric properties of silicon microchannel plates prepared by photo-assisted electrochemical etching (PAECE). The microchannels have a square lattice distribution. The lateral Seebeck coefficient is related to the orientation and is 186 ¿V/K along the edge of the square and 204 ¿V/K when the measurement is performed at 45° with respect to the edge. The Seebeck coefficient in the vertical direction is about one sixth of the lateral value. In order to investigate whether the photonic crystal properties of the silicon microchannels have any influence on the Seebeck coefficient, both microchannel plates with holes tilted 7° with respect to the vertical direction and ordinary silicon microchannel plates are tested. They exhibit a similar thermoelectric behavior. These values are comparable to the value of silicon nanowires at room temperature, making the use of microchannel plates a good alternative to nanowires for temperature sensors.