Extremely narrow nanogaps with a width less than 10 nm have been achieved in Pd thin films on a PDMS substrate by the combination of tensile straining and fine control of initial hydrogen concentration. For the Pd/PDMS structures pre-elongated by 25%, the width of nanogaps was found to decrease with decreasing concentration of the initial feed of hydrogen gas. Hydrogen sensors based on the nanogaps with reduced widths resulted in a dramatic improvement in hydrogen detection limit, and the minimum detection limit obtained in this study was 10 ppm, which is the lowest ever reported for hydrogen sensors employing only a Pd thin film. These results provide an unusual opportunity to use these sensors in specific fields, where ultra-high precision hydrogen detection is required even with one-time use.
Bibliographical noteFunding Information:
This project was supported by Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( 2009-0093823 ) and by the Converging Research Center Program through the Ministry of Education, Science, and Technology (No. 2010K001430 ).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry