Solid State Physics Laboratory

About: Solid State Physics Laboratory is a facility organization based out in Delhi, India. It is known for research contribution in the topics: Quantum dot & Dielectric. The organization has 1754 authors who have published 2597 publications receiving 50601 citations.

The structure and conductivity of binary and ternary glasses (b2o3)1-x-y(Li2O)x(Li2Cl2)y

Abstract: The ionic conductivity of the glasses of the type (B2O3)1-x(Li2O)x and (B2O3)1-x-y(Li2O)x (Li2Cl2)y, has been investigated. In order to understand the superionic properties of these glasses, several experimental techniques have been employed. We present experimental results of density measurements, differential scanning calorimetry, ionic thermocurrents (ITC) and dielectric loss measurements in the frequency range 100–30000 Hz. It appears that the activation energy of the ionic conductivity decreases with increasing Li2O content. The addition of LiCl probably does not influence the glass structure, which will be discussed in some detail. The presence of LiCl in lithium borate glasses, however, causes a drastic increase of the ionic conductivity, which cannot be accounted for by the increased number of charge carriers only. Also the activation energy associated with the conductivity of Li+ ions is reduced by the presence of Cl− ions.

Metal-Insulator Transition in a Disordered Two-Dimensional Electron Gas in GaAs-AlGaAs at Zero Magnetic Field

Abstract: A metal-insulator transition in two-dimensional electron gases at $B\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$ is found in Ga[Al]As heterostructures, where a high density of self-assembled InAs quantum dots is incorporated just 3 nm below the heterointerface. The transition occurs at resistances around ${h/e}^{2}$ and critical carrier densities of $1.2\ifmmode\times\else\texttimes\fi{}{10}^{11}{\mathrm{cm}}^{\ensuremath{-}2}$. Effects of electron-electron interactions are expected to be rather weak in our samples, while disorder plays a crucial role.

Nanotube Tunneling FET With a Core Source for Ultrasteep Subthreshold Swing: A Simulation Study

Abstract: In this article, we propose a novel nanotube (NT) tunneling field-effect transistor with a core source (CSNT-TFET) which uses line tunneling. We systematically investigate the CSNT-TFET with the help of calibrated 3-D simulations and demonstrate that it outperforms the conventional NT-TFET in terms of both static and dynamic performance. We show that the CSNT-TFET exhibits a reduced average subthreshold swing (SS) of 33 mV/decade with Ge-source for more than eight orders of magnitude of drain current at an ultralow supply voltage ( ${V}_{\text {DS}}= {0.3}$ V). In addition, the ON-state current of the CSNT-TFET is enhanced by ~13 times with Si-source and by ~6 times with Ge-source even at ${V}_{\text {DS}}= {V}_{\text {GS}}= {0.3}$ V when compared with the NT-TFET. Without the use of any exotic material for the source and channel regions, the CSNT-TFET offers an impact ionization MOS-like steep SS (a minimum SSpoint of ~1 mV/decade) and a high ON-state current of ~10−6 A for ${V}_{\text {DS}}= {V}_{\text {GS}}= {0.3}$ V. Furthermore, the impact of the gate sidewall spacer and source diameter on the performance of the CSNT-TFET is also investigated.

Characterizing wave functions in graphene nanodevices: Electronic transport through ultrashort graphene constrictions on a boron nitride substrate

Abstract: The nature of localized edge states in edge-disordered graphene nanoconstrictions connected to external leads is studied. Contrary to the general belief, the results show that the localization length is significantly longer than the size of the nanoconstriction, which results into charge spill over into the bulk as well.