Silicon Membranes for Nanophononics

The highly reduced thermal conductivity arising from confinement of acoustic phonons and enhanced phonon scattering in ultra-thin freestanding silicon membranes enables fabrication of sensitive thermal thermoelectric detectors. The devices show very low noise equivalent power of 13 pW/ Hz 1/2 and relatively fast operation. By optimizing the structure and electrical properties of the detector, the operation can approach the temperature fluctuation limit.