Optical, electrical properties and reproducible resistance switching of GeO2 thin films by sol–gel process

Electrical, optical properties and microstructures of GeO2 thin films prepared by the sol–gel method on ITO substrates at different preheating and annealing temperatures have been investigated. All films exhibited GeO2 (101) orientations perpendicular to the substrate surface and the grain size increased with increasing preheating and annealing temperature. The dependence of the microstructure, optical transmittance spectra, optical bandgap and dielectric characteristics on preheating and annealing temperatures was also investigated. Considering the primary memory switching behavior of GeO2, ReRAM based on GeO2 shows promise for future nonvolatile memory applications.