Correlative infrared–electron nanoscopyreveals the local structure–conductivityrelationship in zinc oxide nanowires

摘要

High-resolution characterization methods play a key role in the development, analysis andoptimization of nanoscale materials and devices. Because of the various material properties,only a combination of different characterization techniques provides a comprehensiveunderstanding of complex functional materials. Here we introduce correlative infrared–electronnanoscopy, a novel method yielding transmission electron microscope and infrared near-fieldimages of one and the same nanostructure. While transmission electron microscopy providesstructural information up to the atomic level, infrared near-field imaging yields nanoscale mapsof chemical composition and conductivity. We demonstrate the method’s potential by studyingthe relation between conductivity and crystal structure in Zno nanowire cross-sections. Thecombination of infrared conductivity maps and the local crystal structure reveals a radial freecarrier gradient, which inversely correlates to the density of extended crystalline defects. ourmethod opens new avenues for studying the local interplay between structure, conductivityand chemical composition in widely different material systems.