Hybrid semiconductor/metal nanomembrane superlattices for thermoelectric application

Multilayer systems consisting of periodic hybrid interfaces show promising applications in thermoelectric design in terms of unique phonon blocking and electron conducting features. Universal techniques combining crystalline semiconductors with various categories of metals, oxides, molecules, and polymers have been rarely reported. In this paper, we first briefly review a novel rolled-up and compressing technique based on a strain engineered In0.2Ga0.8As/GaAs semiconducting nanomembrane. Then, the controllable rolling and compressing of a nanomembrane, focused ion beam cutting and the following device fabrication steps are demonstrated for the system of a hybrid In0.2Ga0.8As/GaAs/Cr/Au superlattice. Apart from a considerable reduction of thermal conductivity in a similar system reported by part of us very recently, here our efforts are focused on characterizing the cross-plane electrical conductance of the hybrid superlattice. High electrical conductance of four separated devices show very tight electrical bonding across the hybrid interfaces. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim