Thin Film Transistors (TFTs) have lived to see its significant technological improvement for various display applications in recent years. Carbon nanotube (CNT) based TFT technologies have been found to be a promising component for next generation flexible electronics and flat panel displays in view of CNTs high carrier mobility, device stability and mechanical flexibility. However, the design of CNT-TFT is still not well established, especially with a view to achieve the best performance still protecting thermal stability. In this study, the authors had analysed the device structure and operation of transistor in which carbon nanotubes act as active channel region. CNT-TFT with different device geometrics and CNT physical parameters such as channel length, channel width, CNT tube length, network density and its orientation have been extensively studied using NanoNet simulation tool. This study has thrown new insight into the device performance characteristics of CNT-TFTs. The results show that it is essential to fix the length of the channel more than 5 μm for restricting the device temperature at 300 K and it can be brought down as low as 3 μm if the maximum operating temperature can be 400 K. Comparison with already reported experimental results show that the TFT parameters returned by the simulation experiments and presented

in this paper match closely.

Limitations faced in scaling of silicon-based transistors were expelled using carbon nanotube as channel material. The Carbon nanotube-based thin-film transistor (CN-TFTs) is one of the most promising devices to become successor of silicon devices in near future because of its enhanced device performance in all aspects in nano-regime. The carbon nanotube parameters such as tube length, orientation of tubes between the source and drain terminals, tube density along with channel width and length decide the drain current and device temperature primarily. Therefore, the influence of CNT physical parameters on the CN-TFT device performance were studied. The studies clearly bring out the influence of these parameters on device performance and temperature in addition to suggesting the need to optimize these parameters of the device.

Influence of thickness on structural and optical properties of thermally evaporated Tellurium thin films Polyaniline (PANi) thin films were studied for its use as room temperature ammonia sensor. There are many areas which require sensors to detect the ammonia such as environmental analysis, industries, medical application etc. In the present study, PANi thin films were deposited over glass substrate using thermal evaporation technique at different deposition parameters. The optical transmittance value was 95 % and it has sharp absorbance at 428 nm. The film thicknesses were around 760 nm. Fourier transform infrared spectra (FT-IR) show the presence of amino group and the retention of polymeric chain. The surface of the prepared PANi films is smooth and uniform as analyzed by field emission scanning electron microscopy (FE-SEM). The PANi films shows the response and recovery time as 2-3 min and 2-5 min respectively towards ammonia with a sensitivity of 99.6 %.

Nanocrystalline tellurium (Te) thin films of different thickness were deposited onto thoroughly cleaned glass substrates using conventional thermal evaporation technique. The structural, morphological and the optical properties of the samples were investigated using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and UV-Vis spectroscopy, respectively. The grain size values of the films were increased on increasing the thickness while the strain values were decreased. The optical band gap of the films were varied between 3.92 – 1.3 eV as analyzed by UV-Vis spectroscopy. The refractive index of the film was increasing with increase in thickness. The results were correlated to the decrease in the lattice defects on growing thicker films.