Measuring the Electronic Properties of Materials at the Nanoscale

The general objective of electronic property measurements is to relate extrinsic characteristics of devices or test structures to the intrinsic properties of materials. When there are significant nanoscale inhomogeneities in macroscale materials, or the materials themselves are nanoscale, the measurement of electronic properties at high spatial resolution may be essential to the fundamental understanding of structure–property relationships. This chapter is intended to serve as a framework for the consideration of measuring the electronic properties of materials at the nanoscale, and as a guide to the use of other articles in this volume. Background is provided on general principles of nanoscale measurement, approaches to nanofabrication that enable investigation of nanoscale and nanostructured materials, and distinct regimes of transport that inform the interpretation of electrical measurements. Specific techniques that exploit local probe–sample interactions are introduced according to their principles of operation, to either locally measure characteristics of a material or to generate a local perturbation material that is detected remotely. This framework is used to organize the chapter in terms operational mechanisms of techniques, rather than outcomes of measurement. Noncontact measurements that generate knowledge of local electronic properties are also examined. The chapter is not strictly limited to techniques that provide nanoscale resolution, but rather techniques that resolve electronic properties on length scales over which said properties may vary. The chapter focuses on generally accessible measurements of practical importance to understanding and optimizing the properties of materials with readily envisioned applications.

Keywords: nanomaterials; electrical characterization; scanning probe; semiconductors; nanofabrication; nanostructure; microscopy