Paper BI+AS-MoA10
Transparent Field Effect Sensor with Nanostructured Amorphous In-Ga-Zn-O Wires

Monday, October 19, 2015, 5:20 pm, Room 211D

Amorphous In-Ga-Zn-O (a-IGZO) materials have a wide range of applications in high performance electronic devices, from the active material in thin film transistors for flat-panel displays and as the transducer for field effect sensors. A key benefit of a-IGZO over amorphous silicon is that it enables low processing temperatures, while retaining relatively large electron mobilities, low operating voltages, and very low off currents. In this study, we have fabricated a-IGZO films with well-defined nanostructures using colloidal lithography. These nanostructured a-IGZO films were then patterned into wires using electrohydrodynamic printing of an etch resist followed by wet chemical etching. We have characterized these nanostructured a-IGZO wires using field effect test structures to evaluate their electronic properties. To improve selectivity and stability of the nanostructured a-IGZO wires for sensing applications we have functionalized the back-channel surface with molecular receptors, where glucose oxidase was successfully attached as a sensing enzyme. Depletion/accumulation of carriers in the a-IGZO back-channel was observed upon reaction of the glucose oxidase with the analyte, which leads to significant changes in the sensors electronic signals. Continuous monitoring of glucose concentration can be achieved by measuring a direct change in channel conductance, turn on voltage shift, and/or electrical hysteresis. The results obtained for nanostructured a-IGZO wires will be compared to blanket a-IGZO films, where we have found that the nanostructured a-IGZO wires provide a significant enhancement in sensitivity to subtle changes in glucose concentrations in physiological buffers. These results provide insight into a route to develop low-cost transparent biochemical sensors based on the emerging a-IGZO technology.