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progress. Effect of the variation of nano-inclusion  technique and 2 D-film has been transferred
size, concentration, annealing temperature and       on silicon substrate by using the modified
annealing time on the thermoelectric power           RCA technique. For growth of MoS2 two-
factor and thermal diffusivity are being studied.    zone CVD furnace was used, with sulphur
Significant reduction in thermal diffusivity         and molybdenum trioxide as precursors and
with respect to bulk samples was seen in all         2D film was grown over silicon substrate.
p-type and n-type nano-structured samples.           Raman and photoluminescence characterisation
Significant improvement in thermoelectric            confirmed growth of single and few layer
power factor of n-type nano-composites with          MoS2 film.
Si nano-inclusions (0.2 wt%) over bulk samples
at low temperature was obtained.                     Carbon Nano Tube (CNT) based NOx and
                                                     Ammonia Sensors
Development of Gallium Nitride (GaN)-based
MMICs for Applications upto X-band                        Fabrication of CNT sensing element over robust
                                                     membrane: CNT sensors of different geometries (both
     GaN HEMT process technology developed           with single as well as multiple sensor elements
at SSPL has been successfully implemented at         arranged as arrays) have been fabricated over
GAETEC. Repeatable performance in DC and             porous alumina membranes using conventional
RF characterisation and output power density         photolithography. Each device of size varying
has been achieved up to C-band in Power              from 2 mm X 2 mm to 6 mm X 6 mm had
HEMTs fabricated by indigenous technology. A         variable patterns and geometry. These individual
major milestone has been achieved through the        devices will be mounted by die-bonding and
integration of source and gate connected field       wire bonded on to a header to obtain a packaged
plates in the HEMT device structures that yielded    CNT sensing device. To introduce selectivity
two fold higher (Vb)off of 160V with a resultant     for ammonia and NO2, initial experiments of
enhancement of device performance enabling           functionalization with metal oxides (CuO, SnO2)
successful device operation at 50 V drain bias.      and polymers (polyaniline) is being carried out.
Earlier, the devices could be operated only up to    Devices have been fabricated using fuctionalised
28 V drain bias. GaN HEMTs delivering 5W/mm          CNTs also.
at 28 V and 10 W/mm at 50 V operations are
available. 1.7-2.1 GHz highly linear 10 W power      (A) (B)  (C)
amplifier has been developed for application in
tropo-scatter communication. Initial GaN HEMT                    (A) Fabricated membrane with different devices
devices developed at SSPL have been used for                             (B) A sensor array with four elements
the driver stage.
                                                                   (C) An array mounted on PCB (sensor device)
Enabling Technologies for 2-D Films and
Devices for THz and Optoelectronics                       Sensor characterisation and Electronics development:
                                                     A shield-based PCB with Arduino Due/Mega
     The Project objectives and scope includes       microcontroller boards has been fabricated
growth of good quality 2-D films and development     and configured for measuring the change in
of THz modulator, THz detector and fabrication       resistance of the CNT-TFR. This electronics has
of MoS2 FET on flexible substrate. Growth            the capability of controlling different cycles
of 2 D films of graphene and MoS2 has been           of sensing (both exposure and recovery) by
obtained and transfer of graphene over silicon       controlling the sequential switching of components
substrate has also been carried out. Initial         such as, miniature valves and Pumps, UV Light
masks have been fabricated for electrical            Emitting Diode (LEDs) etc. as well as to vary
characterisation and development of FET and
other devices of 2 D materials. Graphene
monolayer has been grown on Cu-foil by Low
Pressure Chemical Vapor Deposition (LPCVD)

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