Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 13 of 13

  • Phosphorous passivation of the SiO2/4H–SiC interface

    Y.K. Sharma   A.C. Ahyi   T. Issacs-Smith   X. Shen   S.T. Pantelides   X. Zhu   L.C. Feldman   J. Rozen   J.R. Williams  

    We describe experimental and theoretical studies to determine the effects of phosphorous as a passivating agent for the SiO 2/4H-SiC interface. Annealing in a P 2O 5 ambient converts the SiO 2 layer to PSG (phosphosilicate glass) which is known to be a polar material. Higher mobility (approximately twice the value of 30-40 cm 2/Vs obtained using nitrogen introduced with an anneal in nitric oxide) and lower threshold voltage are compatible with a lower interface defect density. Trap density, current-voltage and bias-temperature stress (BTS) measurements for MOS capacitors are also discussed. The BTS measurements point to the possibility of an unstable MOSFET threshold voltage caused by PSG polarization charge at the O-S interface. Theoretical considerations suggest that threefold carbon atoms at the interface can be passivated by phosphorous which leads to a lower interface trap density and a higher effective mobility for electrons in the channel. The roles of phosphorous in the passivation of correlated carbon dangling bonds, for SiC counter-doping, for interface band-tail state suppression, for Na-like impurity band formation and for substrate trap passivation are also discussed briefly. [All rights reserved Elsevier].
    Download Collect
  • Stock loss studies on breathing loss of gasoline

    Y.K. Sharma   Arakshita Majhi   V.S. Kukreti   M.O. Garg  

    Volatile nature of gasoline is the prime reason for various kinds of losses, which occur during the course of retailing operation. Standing storage or breathing loss, the expulsion of hydrocarbon vapors, occurs during tranquil condition from the gasoline storage tank. Estimation of breathing loss is vital as it occurs endlessly, consequently affecting the environment and economy of the nation. Present study proposes an empirical model to evaluate breathing loss of under ground storage (UGS) and above ground storage (AGS) tanks using easily accessible variables.
    Download Collect
  • Stock loss studies on breathing loss of gasoline

    Y.K. Sharma   Arakshita Majhi   V.S. Kukreti   M.O. Garg  

    Volatile nature of gasoline is the prime reason for various kinds of losses, which occur during the course of retailing operation. Standing storage or breathing loss, the expulsion of hydrocarbon vapors, occurs during tranquil condition from the gasoline storage tank. Estimation of breathing loss is vital as it occurs endlessly, consequently affecting the environment and economy of the nation. Present study proposes an empirical model to evaluate breathing loss of under ground storage (UGS) and above ground storage (AGS) tanks using easily accessible variables.
    Download Collect
  • Laser action in praseodymium doped zinc chloride borophosphate glasses

    Y.K. Sharma   S.P. Tandon   S.S.L. Surana  

    In order to predict laser action in praseodymium doped zinc chloride borophosphate glasses with the help of laser parameters both absorption and fluorescence spectra have been studied. The glass specimens having composition in mol% B 2O 3(14.57)-P 2O 5(44.85)-Na 2O(26.08)-ZnCl 2 (14.50)-Pr 6O 11(R)(R=0.0,0.1 and 0.2 mol%) have been prepared by melt quenching technique. The spectra consist of seven absorption bands (400-2400 nm) and three fluorescence bands (400-700 nm). The observed optical spectra are discussed in terms of energy states and the intensity of the transitions. The various energy interaction parameters like Slater-Condon, Lande, Racah and bonding parameters have been computed. Judd-Ofelt intensity parameters and laser parameters have also been calculated. A comparison with phosphate glass shows a considerable increase (by a factor of ~2.5) in the value of stimulated emission cross-section, sigma p, of the transition 3P 0rarr 3F 2 in zinc chloroborophosphate glass
    Download Collect
  • Spectroscopic and radiative properties of Sm3+ doped zinc fluoride borophosphate glasses

    Y.K. Sharma   S.S.L. Surana   R.P. Dubedi   V. Joshi  

    Sm 3+ doped zinc fluoride borophosphate glasses of composition in mol.% P 2O 5(39.77)-Na 2O (17.38)-Al 2O 3(16.67)-B 2O 3 (15.44)-ZnF 2(10.74)-Sm 2O 3(x) where x=0.0, 0.2, 0.3 and 0.5 have been prepared by melt quenching technique. Optical absorption and fluorescence spectra have been reported. Judd-Ofelt approach has been applied for the fharrf transitions of Sm 3+ to evaluate various Omega lambda (lambda=2, 4, 6) parameters. Using the fluorescence data and these Omega lambda parameters, various radiative properties for different emission lines have been evaluated. The values of radiative properties indicate that 4G 5/2rarr 6H 9/2 transition in Sm 3+ doped zinc fluoride borophosphate glass may be used in the development of light emitting diodes (LEDs) highly useful in optical communication. The bonding environment surrounding the rare earth (RE) ion has also been discussed. [All rights reserved Elsevier]
    Download Collect
  • Spectroscopic investigations and luminescence spectra of Sm3+ doped soda lime silicate glasses

    Y.K. Sharma   S.S.L. Surana   R.K. Singh  

    Download Collect
  • Spectral studies of erbium doped soda lime silicate glasses in visible and near infrared regions

    Y.K. Sharma   S.S.L. Surana   R.K. Singh    R.P. Dubedi  

    Optical absorption and photoluminescence spectra of Er3+ doped soda lime silicate glasses of the composition (in wt.%) 68.94SiO2–22.55Na2O–1.91CaO–4.96K2O–0.85B2O3–0.29As2O3–xEr2O3 where x = 0.0, 0.2, 0.3 and 0.5 have been studied in the UV–VIS/NIR regions. From the measured intensities of the various absorption bands of these glasses, the Judd–Ofelt parameters Ω2, Ω4 and Ω6 have been evaluated. Judd–Ofelt theory has been successfully applied to characterize the absorption and luminescence spectra of these glasses. From this theory various radiative properties like spontaneous emission probability, radiative life time, fluorescence branching ratio and stimulated emission cross-section for various emission bands of these glasses in the visible and NIR spectral regions have been determined and reported. An attempt has been made to through some light on the environment of Er3+ in this glass system. Radiative properties of fluorescence band at 1.54 μm suggest the suitability of this glass system for broadband amplifier in the third telecom window.
    Download Collect
  • Spectral studies of erbium doped soda lime silicate glasses in visible and near infrared regions

    Y.K. Sharma   S.S.L. Surana   R.K. Singh   R.P. Dubedi  

    Optical absorption and photoluminescence spectra of Er 3+ doped soda lime silicate glasses of the composition (in wt.%) 68.94SiO 2-22.55Na 2O-1.91CaO-4.96K 2 O-0.85B 2O 3-0.29As 2O 3- xEr 2O$ d3 where x=0.0, 0.2, 0.3 and 0.5 have been studied in the UV-VIS/NIR regions. From the measured intensities of the various absorption bands of these glasses, the Judd-Ofelt parameters Omega2, Omega4 and Omega6 have been evaluated. Judd-Ofelt theory has been successfully applied to characterize the absorption and luminescence spectra of these glasses. From this theory various radiative properties like spontaneous emission probability, radiative life time, fluorescence branching ratio and stimulated emission cross-section for various emission bands of these glasses in the visible and NIR spectral regions have been determined and reported. An attempt has been made to through some light on the environment of Er 3+ in this glass system. Radiative properties of fluorescence band at ~1.54mum suggest the suitability of this glass system for broadband amplifier in the third telecom window. [All rights reserved Elsevier]
    Download Collect
  • Influence of methanol extraction on the stability of middle distillate fuels

    Y.K. Sharma   K.M. Agrawal  

    The stability of six middle distillate fuel samples before and after extraction with methanol under conditions of accelerated ageing were determined. Extraction reduced the tendency of the fuels to form insolubles. The effect was more pronounced for catalytically cracked light cycle oil.
    Download Collect
  • Scaling law for hot-carrier injection in insulators

    Y.K. Sharma   B.B. Srivastava  

    Download Collect
  • Thermal noise in the trap free insulated diode with thermal free carriers

    Y.K. Sharma  

    Download Collect
  • Exact J/V characteristic of an insulator diode with thermal free carriers in nonconstant mobility regime

    V.S. Raghav   Y.K. Sharma  

    An exact analytical expression for the current/voltage characteristic has been evaluated for an insulator containing significant density of thermally generated free carriers and operating under a nonconstant mobility regime. It is shown that the complete characteristic can be divided into three separate regimes clearly.
    Download Collect
  • Space charge limited current in an insulator at high fields

    Y.K. Sharma  

    It is shown that the correct high field current/voltage characteristic in space charge limited single-injection solid state diodes is obtained at sufficient high fields.
    Download Collect
1

Contact

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback