The technology of modification of the CNT array on a silicon substrate using laser radiation of nanosecond duration has been developed. The energy regime of irradiation of the array is determined with the aim of aligning the nanotubes perpendicular to the substrate. Structuring of CNTs at a given area using impulse nanosecond radiation moving using a galvanometric scanner system is obtained. Patterning was carried out using pulsed laser radiation with a wavelength of 1064 nm, which was moved by means of galvanometric mirrors over the area of the CNT array. The spatial profile of the beam was Gaussian. The energy density of the pulse was in the range 0.4-2.2 J/cm2. In order to obtain a homogeneous region of the CNT array after irradiation, the following parameters were set: the pulse duration was 100 ns, the radiation frequency was 30 kHz, at which the overheating of CNTs was minimized. The diameter of the laser beam at the focus of the laser was 20 μm. The moving rate of the laser beam of 500 mm/s was chosen in such a way so that individual pulses formed a continuous line with a laser beam overlap to compensate the changing in laser spot power along the diameter. Thus, the processed square 5×5 mm was formed by parallel lines 5 mm long, consisting of individual pulses located at a distance of 17 μm from each other. It is shown that the following effects are possible: CNT ablation, the effect of CNT alignment (straightening), singling, and “splicing” of individual CNTs in a single structure, as well as changing the morphology of the array itself. Nanotubes are less defective after laser modification. This is proved by Raman spectroscopy. The effect of CNT array structuring can be used to create new sensitive elements of photodetectors, solar cells, chemical sensors, temperature and pressure sensors, probes in microscopy and emitters.
Presently laser radiation is widely used in the variety of fields. This indicates the necessity of the control the intensity of laser radiation. In this case use the sensors - devices that convert laser radiation into an electronic signal. Using carbon nanotubes (CNTs) in sensor design is perspective direction, which can lead to of creating devices with impressive parameters.
A method based on electrophoretic deposition (EPD) has been developed to produce uniform and local deposits of multiwalled carbon nanotubes (CNT) on interdigital structures of planar supercapacitor (SC) at room temperatures. Alcohol/acetone suspensions were used under constant voltage conditions in the range of 6 to 100 V, with deposition times ranging from 2 to 60 minutes and electrodes space from 2 to 15 mm. It was shown that for dense layers deposition with good adhesion on the narrow lines of the planar SC electrodes it is necessary to use average values of the electric field and multi-stage method in which the deposition and drying processes are alternated. Electrochemical tests of the sandwich-like supercapacitors with electrodes obtained by the described method were carried out. The specific capacity of experimental samples increased from 0.24 to 1.07 mF/cm2 with an increase in the number of EPD cycles from 3 to 9.
This work is devoted to the CVD-synthesis of arrays of carbon nanotubes (CNTs) on Co-Zr-N-(O), Ni-Nb-N-(O), Co- Ta-N-(O) catalytic alloy films from gas mixture of C2H2+NH3+Ar at a substrate temperature of about 550°C.Heating of the amorphous alloy causes its crystallization and squeezing of the catalytic metal onto the surface. As a result, small catalyst particles are formed on the surface. The CNT growth takes place after wards on these particles. It should be noted that the growth of CNT arrays on these alloys is insensitive to the thickness of alloy film, which makes this approach technically attractive. In particular, the possibility of local CNT growth at the ends of the Co-Ta-N-(O) film and three-level CNT growth at the end of more complex structure SiO2/Ni-Nb-N-O/SiO2/Ni-Nb-N-O/SiO2/Ni-Nb-N-O/SiO2 is demonstrated.
The technology of production of matrix photoreceivers based on carbon nanotubes (CNTs) consisting of 16 sensitive elements was developed. Working wavelength range, performance and sensitivity were studied.
Photodetector based on carbon nanotubes (CNT) was investigated. Sensors were done on quartz and silicon
susbtrate. Samples of photodetectors sensors were produced by planar technology. This technology included deposition
of first metal layer (Al), lithography for pads formation, etching, and formation of local catalyst area by inverse
lithography. Vertically-aligned multi-wall carbon nanotubes were directly synthesized on substrate by PECVD method.
I-V analysis and spectrum sensitivity of photodetector were investigated for 0.4 μm - 1.2 μm wavelength. Resistivity of
CNT layers over temperature was detected in the range of -20°C to 100°C.
In this work showed the possibility of creation high capacity thin-film lithium batteries with the Si-CNT nanocomposite anodes. Synthesized multiwall carbon nanotubes were covered by amorphous silicon with magnetron sputtering. Developed method of formation nanostructured composite is simple, efficient and compatible with widely spread equipment. As s result, designed anode structures with deposited Si thickness of 260 and 390 nm exhibit high specific capacities (more than 2500 mAh/g) and significantly improved cycling stability versus silicon films.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.