Development of a high throughput impedance measurement device for new materials discovery

Doped perovskites are a material of interest due to their ability to conduct protons in a temperature range desirable for intermediate temperature fuel cell applications. Despite much research aimed at improving the performance of these materials, the contributions of various material parameters to the conductivity are not well understood. In the case of Y-doped BaZrO3, published reports often disagree about its conductivity and structure. By employing combinatorial methods, the effect of compositional or process variations can be studied in a more rapid manner in order to identify potential candidate compositions, and possibly gain a better understanding of the material. In this work, a high-throughput impedance test cell was designed and built in order to test thin film samples by electrical impedance spectroscopy. Blanket thin film samples deposited by pulsed laser deposition (PLD) were created and tested, and a masking scheme was developed for fabrication of combinatorial libraries. Testing with the high-throughput cell revealed challenges to ensure the quality of acquired data, and the importance of the quality of electrical contact being made with the library wafers. For samples where high film quality was combined with reliable contacts, calculated properties for conductivity and activation energies were in agreement with literature values. Testing on BaZr0.9Y0.1O2.95 (BYZ10), a candidate electrolyte for intermediate temperature fuel cell applications was inconclusive due to experimental difficulties in obtaining high quality data. It is recommended that the for improved cell performance, refinement of the contact design is needed in order to facilitate more robust electrical contact between the cell and the wafer.