Sophisticated gas sensor devices for point of interest applications. Members of the Laboratory for Emerging Nanometrology (LENA) from the TU Braunschweig (Institute for Semiconductor Technology) in cooperation with groups of the Fraunfofer IWM, University of Barcelona and TU Clausthal have developed the first sensor system that unifies selective detection and energy harvesting properties, using defined organic-inorganic hybrid materials.
The sensor device is composed by a signal generation (nanostructured p-Si/n-ZnO solar cell) and a sensor unit (n-ZnO nanowires functionalized with defined organic self assembled monolayers; SAM). Upon light illumination, the solar cell unit generates a an open circuit voltage (Voc). With the introduction of the target gas species, selective SAM-gas binding interactions are varying the electronic structure of the attached n-ZnO nanowires, and thus, alter the self generated signal of the p-Si/n-ZnO solar cell unit to indicate the presence of the target gas, namely nitrogen dioxide (NO2).
Theoretical simulations of chemical binding interactions and the consequent electronic surface modulation enabled an insight into the complex sensing mechanism of selective gas detection. These novel insights into the mechanism of selective gas-hybrid material interactions opens a new route towards the development of selective gas sensors.
Publication:
M. W. G. Hoffmann, L. Mayrhofer, O. Casals, L. Caccamo, F. Hernandez-Ramirez, M. Moseler, A. Waag, H. Shen, J. D. Prades
Highly selective and self-powered gas sensor enabled via organic surface functionalization
Advanced Materials (2014)
DOI: 10.1002/adma.201403073.
Contact:
Prof. Andreas Waag
Institute for Semiconductor Technology
Laboratory for Emerging Nanometrology
Technische Universität Braunschweig
Hans-Sommer-Straße 66
38106 Braunschweig
Phone: (+49)531 391 3773
Email: a.waag@tu-braunschweig.de
www.tu-braunschweig.de/iht