Axial resistivity measurement of a nanopillar ensemble using a cross-bridge Kelvin architecture

Achieving the full potential of nanopillar electrode based devices, such as next-generation solar cells, catalyst supports, and sensors, requires axial resistivity measurements to optimize electronic performance. Here, the authors demonstrate a technique for direct measurement of the ensemble electrical properties of nanopillar thin films along the structure's longitudinal axis. A cross-bridge Kelvin resistor architecture is adapted to accommodate an indium tin oxide (ITO) nanopillar thin film fabricated by glancing angle deposition (GLAD). As-deposited GLAD ITO nanopillars were found to have a measured resistivity of (1.1 ± 0.3) × 10−2 Ω cm using our technique. Planar ITO films deposited at near normal incidence were found to have a resistivity of (4.5 ± 0.5) × 10−3 Ω cm, determined by the standard four-point-probe technique. These measurements demonstrate the viability of this modified technique for nanopillar characterization, and identify experimental limitations related to device size and edge defects.