Investigation of digitally printed copper electrodes

This master’s thesis focuses on the application of Print-Light-Synthesis (PLS) toward the fabrication of low cost, highly reproducible, and environmentally friendly Cu-based thin films. This work aims to investigate a copper precursor that, once deposited in an ink on a substrate can undergo photochemical and/or photothermal reduction for transformation of the precursor into a Cu-based solid. The as-fabricated copper based thin films are characterized to evaluate their physical-chemical properties, with the aim of identifying the Cu species present in the samples (Cu0, Cu+1, Cu2+ and others) which are primarly Cu0, Cu2O, CuO and Cu(OH)2. First, drop-casted Cu(CH3COO)2 ink patterns are prepared and irradiated with UV-light, followed by spectroscopic analysis using X-ray Photoelectron spectroscopy (XPS). Cu-based patterns with different Cu(CH3COO)2 loading (around 100 or 200 μg/cm2) are fabricated with PLS and analyzed by XPS applying and performing XPS spectral fitting for the qualitative and quantitative analyses. Scanning electrochemical microscopy is applied to Cu-based thin films to evaluate the micrometric reactivity of the PLS-Cu patterns. Finally, cyclic voltammetry is performed to investigate and evaluate the possible applications of the final Cu-based thin films as electrodes.