New Dynamic Air-Brush Technique for SWCNTs Deposition: Application to Fabrication of CNTFETs for Electronics and Gas Sen
- PDF / 1,910,419 Bytes
- 9 Pages / 612 x 792 pts (letter) Page_size
- 51 Downloads / 174 Views
New Dynamic Air-Brush Technique for SWCNTs Deposition: Application to Fabrication of CNTFETs for Electronics and Gas Sensing 1
P.Bondavalli, 1L.Gorintin, 1P. Legagneux, 2J.P.Simonato , 2L.Cailler Nanocarb Lab., Physics Department, Thales Research and Technology, Palaiseau, France 2 LITEN / DTNM / LCH, CEA-Grenoble Grenoble, France. 1
[email protected] ABSTRACT This contribution deals with Carbon Nanotubes Field Effect transistors (CNTFETs) based gas sensors fabricated using a completely new dynamic spray based technique (patented) for SWCNTs deposition. The extreme novelty is that our technique is compatible with large surfaces, flexible substrates and allows to fabricate high performances transistors exploiting the percolation effect of the SWCNTs networks achieved with extremely reproducible characteristics. Recently, we have been able to achieve extremely selective measurement of NO2, NH3 and CO using four CNTFETS fabricated using different metals as electrodes, exploiting the specific interaction between gas and metal/SWCNT junctions. In this way we have identify an electronic fingerprinting of the gas detected. The response time is evaluated at less than 30sec. INTRODUCTION Carbon nanotubes are one dimensional molecular structures obtained by rolling up one graphene sheet (Single-Wall-Carbon-NanoTube, i.e. SWCNT) or more (Multi-Wall-Carbon-NanoTube, i.e. MWCNT). Since their discovery in 1991 [1], many scientific teams have focused their interest on this material which shows extraordinary physical properties. Actually, CNTs have demonstrated very high carrier mobility in field effect transistors [2], a very high electromigration threshold (108 –109 A/cm2 [3]), a very high thermal conductivity (for one single, it can reach 3000W/A K [4-6]) and exceptional mechanical properties (the measured specific tensile strength of a single shell of a MWCNT can be as high as 100 times that of steel [7]). Therefore, they are studied for a lot of applications: for field emission devices [8-12], in composites to improve electrical or thermal management, mechanical resistance [13,14], for electronic devices, to replace silicon based transistors [15, 16] and finally, for chemical and biological sensors [1719]. Concerning this last application, different kind of gas/chemical sensors, based on different working principles, have been fabricated thanks to CNTs : miniaturized ionizing gas sensors (also called “micro-gun” sensors) [20], CNT thin films with variable resistance as a function of the adsorbed gas properties [21-24] and finally Carbon Nanotube Field Effect Transistor (CNTFET) based sensors. The main advantages for CNTFET based sensors, compared to existing technologies, are numerous: devices can be made ultra compact, effective at room temperature, with low power consumption, very fast response, low recovery time (few seconds) and show a good versatility (they can be used for several gases). Finally we can achieve relatively low cost fabrication (using a CMOS compatible technology).
We have to point out th
Data Loading...
