InGaN as a Substrate for AC Photoelectrochemical Imaging

Abstract

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.

Keywords

• photoelectrochemistry
• ingan/gan epilayer
• cell imaging
• light-activated electrochemistry
• light-addressable potentiometric sensor