On-substrate fabrication of a self-activated nanostructured ZnO gas sensor.

Gaining rational control over bottom-up device fabrication processes is necessary to achieve high-performance devices and overcome technical obstacles. Among these is the need for activation of metal oxide gas sensors (GSs) by an external heating source, which limits their miniaturization and integration. A well-controlled, seedless, and position-selective hydrothermal method to fabricate high-performance self-activated zinc oxide (ZnO) nano-needle (ZNN) GSs directly on a substrate was developed.