Record High Power Factor and Low Thermal Conductivity in Amorphous/PbTe/Amorphous Multiple Quantum Wells

Abstract Quantum well (QW) superlattice is one of the proposals to improve the thermoelectric properties and provide a rich platform for the next generation of thermoelectric device. Previous QW have two main challenges that need to be addressed: i) decrease the electron tunneling across the layers in the semiconductor‐based multiple QWs (MQW), and ii) decrease the thermal conductivity in the oxide‐based MQW. Herein, the study demonstrates amorphous based PbTe/amorphous‐STO MQWs with ultrahigh power factor of 40.9 µW cm −1 K −2 and record low thermal conductivity of ≈0.49 W m −1 K −1 at room temperature. The high performance of PbTe/amorphous‐STO MQWs is attributed to strong quantum confine effect and its intrinsic low thermal conductivity of amorphous superlattice structure. The results open up a new avenue toward modulating thermoelectric properties beyond traditional MQWs of thermoelectric materials.