One-step transfer printing of patterned nanogap electrodes

Direct printing of nanogap-separated metallic contact pairs is described that enables novel nanoelectronic device architectures. Nanotransfer printing (nTP) stamps are grown by molecular beam epitaxy involving layered III-V semiconductors that are selectively etched. Finished stamps comprise both the nanoscale surface trench that becomes the nanogap on printing and a microscale, predetermined geometry that affords the simultaneous integration of contact pads for external electrical testing. This nTP technique is well suited for top-contacting sensitive thin films for electrical characterization; a typical electrode configuration is illustrated by transfer-printed 13 nm thin metal films that are separated by an electrically insulating gap of ca. 30 nm.