BITS Faculty Publications

Permanent URI for this communityhttp://localhost:4000/handle/123456789/1867

Browse

Subject: search.filters.subject.Device modeling

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Device Modeling of Double Layered TiO2 Nanotube Array Based Resistive Vapor Sensor
    (IEEE, 2018) Hazra, Arnab
    Single and double layered TiO 2 nanotube array were synthesized by anodic oxidation method. Anodization voltage was varied to develop double layered TiO 2 nanotube array. Developed materials were characterized structurally and morphologically by X-ray diffraction spectroscopy (XRD)and field emission scanning electron microscopy (FESEM)respectively. Sandwich structure devices with Au top electrode and Ti bottom electrode were fabricated by using both single and double layered TiO 2 nanotubes for vapor sensing application. A simplified device modeling was introduced to establish the sensing mechanism of both the TiO 2 nanotube arrays. Additional interlayer junctions in double layered TiO 2 nanotubes array, enhanced the vapor sensing performance significantly. Double layered TiO 2 nanotubes array was able to show 92.4% of response magnitude for ethanol concentration of 160 ppm at 300 K where 55.2% response was observed for mono-layered TiO 2 nanotube array.
  • No Thumbnail Available
    Item
    Investigation into gate dielectric material using different optimization techniques in carbon nanotube field effect transistors
    (Journal of Micromechanics and Microengineering, 2019) Navneet, Gupta
    This paper presents an analysis of gate dielectric materials using different optimization techniques for carbon nanotube field effect transistors. The selection of the best gate dielectric is done using multi-criteria decision-making methods, i.e. Ashby's, TOPSIS (technique for order preference by similarity to ideal solution) and VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje in Serbian). The selection criteria for the best dielectric material are based on various material indices which include relative dielectric constant (εr), energy band gap (Eg), conduction band offset and coefficient of thermal expansion. This analysis concludes that lanthanum oxide (La2O3) is the most promising dielectric material, followed by HfO2. All these material selection methodologies converge on the same results. This result is compared with the experimental findings, and the close match between analytical and experimental results confirms the validity of this study.
  • No Thumbnail Available
    Item
    A Simplified Surface Potential Based Current Model for Gate-All-Around Carbon Nanotube Field Effect Transistor (GAA-CNFET)
    (2021) Gupta, Navneet
    This paper presents a simple surface-potential based drain current (Id) model for gate-all-around carbon nanotube field effect transistor (GAA-CNFET). The model captures a number of features which include ballistic transport, first subband minima, chirality and non-existence of fringing and screening effect due to its geometry. Further, the effect of chirality on subthreshold swing (SS), current on/off ratio (ION/OFF) and transconductance (gm) is studied by extracting these parameters from drain current variation. It is observed that there exists a trade-off between the parameters for different chiral vector CNTs. As chirality increases, transconductance and subthreshold slope increases while current on/off ratio reduces. To confirm the validity of proposed model, virtually fabricated GAA-CNFET device performance was simulated and compared with the calculated values. The variation is also compared with the experimental result of actually fabricated device. The close match between calculated, simulated and experimental results confirms the validity of the proposed model.