Sensors (Oct 2019)

InGaN as a Substrate for AC Photoelectrochemical Imaging

  • Bo Zhou,
  • Anirban Das,
  • Menno J. Kappers,
  • Rachel A. Oliver,
  • Colin J. Humphreys,
  • Steffi Krause

DOI
https://doi.org/10.3390/s19204386
Journal volume & issue
Vol. 19, no. 20
p. 4386

Abstract

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AC photoelectrochemical imaging at electrolyte−semiconductor interfaces provides spatially resolved information such as surface potentials, ion concentrations and electrical impedance. In this work, thin films of InGaN/GaN were used successfully for AC photoelectrochemical imaging, and experimentally shown to generate a considerable photocurrent under illumination with a 405 nm modulated diode laser at comparatively high frequencies and low applied DC potentials, making this a promising substrate for bioimaging applications. Linear sweep voltammetry showed negligible dark currents. The imaging capabilities of the sensor substrate were demonstrated with a model system and showed a lateral resolution of 7 microns.

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