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Rezaee Rokn-Abadi, M.
- Hydrogen Sensing Properties of Indium Doped Tin Oxide Thin Films Deposited by Spray Pyrolysis
Abstract Views :482 |
PDF Views:125
Authors
Affiliations
1 Physics Department, Ferdowsi University of Mashhad, Mashhad, IR
1 Physics Department, Ferdowsi University of Mashhad, Mashhad, IR
Source
Indian Journal of Science and Technology, Vol 3, No 1 (2010), Pagination: 14-16Abstract
In this article the effect of indium impurity on tin oxide layers sensitivity have been studied. Tin oxide thin films without impurity and with different impurities are deposited by spray pyrolysis method and their structural layers have been characterized by x-ray diffraction spectrum and SEM technology. In different temperature we have calculated layer sensitivity. It is found that the most sensitivity is in the sample of 6% impurity at temperature of 200°C. With increasing of impurity concentration the work temperature is decreased until in the 15% impurity sample the work temperature is decreased to 100°C.Keywords
Tin Oxide, Spray Pyrolysis, Thin FilmsReferences
- Keshmiri SH (1996) Characterization of transparent conducting oxides, 4th Intl. Sym. on Adv. Materials, Islamabad, Pakistan. pp: 459-462.
- Keshmiri SH and Rezaee-roknabadi M (2002) The surface and materials science of thin oxide. Thin Solid Films. 413, 167-170.
- Lewis BG and Paine DC (2000) Applications and processing of transparent conducting oxides. MRS 6 Bull. 25, 22-29.
- Pankove J I (1978) Characterization of semiconductor material and devices. Appl .Phys. Lett. 32, 32-35.
- Pankove JI (1991) Semiconductors and Semimetals. 34, Academic Press. pp: 35-43.
- Poortmans P, Rosemeulen M, Kaniava A, Vanhellemont J, Elgamel H and Nijs J (1995) Defect and impurity engineered semiconductors and devices. Materials Res.Soc. Symp. Proc. pp: 399-411.
- Raniero L (2006) ZnO-based transparent thin film transistor, Thin Solid Films. 65, 295-298.
- Schubert EF (1993) Doping in III–V semiconductors. Cambridge University Press, Cambridge.
- Swanepoel RJ (1980) Transparent electronics. J. Phys. E: Sci. Instrum. 16, 1214-1219.
- Wagner JF (2003) Structural electrical and optical properties of undoped and indium doped ZnO thin films. Transparent Electronics, Science. 300, 1245-1247.
- Aasmundtveit KE, Samuelsen EJ, Pettersson LA, Inganas O, Johansson T and Feiderhans R (1999) Chemical vapour deposition of thin oxide thin films. Synth.Met. 101, 561-566.
- Hot Electron of Steady-state Transport in Submicrometer ZnSe and ZnS N+-i(n)-n+ Diodes
Abstract Views :452 |
PDF Views:92
Authors
Affiliations
1 Physics Department, Ferdowsi University of Mashhad, Mashhad, IR
2 Physics Department, Shahrood University of Technology, Shahrood, IR
1 Physics Department, Ferdowsi University of Mashhad, Mashhad, IR
2 Physics Department, Shahrood University of Technology, Shahrood, IR
Source
Indian Journal of Science and Technology, Vol 3, No 1 (2010), Pagination: 37-40Abstract
Monte Carlo simulation of steady-state electron transport in ZnSe and ZnS diodes of n+-i(n)-n+ structure with a 0.2 µm active layer length is described. The anode voltage ranges from 1 to 5 V. The distributions of electron energies and electron velocities, and the profiles of the electron density, electric field, potential and average electron velocity are computed. Based on these data, the near ballistic nature of the electron transport in the 0.2 µm long diode and the importance of the back-scattering of electrons from the anode n+-layer are discussed. Also, the effects of the lattice temperature and doping on the length of the active layer are discussed. Our calculations show that electron reach to a higher drift velocity in the ZnSe than ZnS. So ZnSe material is a good candidate for high power device fabrication.Keywords
Active Layer, Diode, Drift Velocity, BallisticReferences
- Arabshahi H, Khalvati MR and Rezaee Rokn-Abadi M (2008) Comparison of steady state and transient electron transport in InAs, InP and GaAs. Modern Phys.Lett. B. 22 (17), 1695-1702.
- Arabshahi H, Khalvati MR and Rezaee Rokn-Abadi M (2008) Monte Carlo modeling of hot electron transport in bulk AlAs, AlGaAs and GaAs at room temperature. Modern Phys. Lett. B. 22 (18), 1777-1784.
- Besikci B, Bakir M and Tanatar U (2000) Hot electron simulation devices. J. Appl. Phys. 88 (3), 1243-1247.
- Bhapkar U V and Shur M S (1997) Ensemble Monte Carlo study of electron transport in wurtzite In. J. Appl. Phys. 82, 1649-1654.
- Bhuiyam S, Senoh M and Mukai T (2003) Comparison of steady state and transient electron Appl. Phys. Lett. 62, 2390-2395.
- Brennan K, Hess K, Tang JY and Iafrate GT (1983) High field electron transport properties. IEEE Trans.Electron Devices, 30, 1750-1755.
- Fischetti MV and Laux SE (1991) Low field electron mobility in GaN. IEEE Trans.Electron Devices, 38, 650-655.
- Foutz BE, Eastman LE, Bhapkar UV and Shur M (1997) Full band Monte Carlo simulation of Zincblende GaN MESFET’s including realistic impactionization rates. Appl. Phys. Lett. 70, 2849-2854.
- Ghani B, Hashimoto A and Yamamoto A (2003) High temperature characteristics of AlGaN/GaN modulation doped field-effect transistors. J. Appl.Phys. 94, 2779-2783.
- Izuka J and Fukuma M (1990) Full-band polar optical phonon scattering analysis and negative differential conductivity in wurtzite GaN. Solid-State Electron, 3,27-33.
- Jacoboni J and Lugli P (1989) The Monte Carlo method for semiconductor and device simulation. Springer-Verlag.
- Jacoboni J and Reggiani L (1983) The Monte Carlo simulation of Semiconductor and Devices. Rev. Modern Phys. 55 (3), 665-663.
- Kane EO (1957) Band structure calculation in group III and IV materials. J.Phys.Chem. Solids. 1, 249-253.
- Martienssen M and Warlimont H (2005) Springer hand book of condensed Matter and Materials Data, Springer.
- Newman N, Schilfgaarde V, Kendelewicz T and Spicer WE (1989) GaN based transistor for high power applications. Mater. Res. Soc. Symp. Proc. 21, 54-59.
- Ridley BK (1993) Quantum processes in semiconductors. Clarendon Press. Oxford.
- Vurgaftman I and Meyer JI (2001) A review for GaN based devices. J. Appl. Phys. 89(11), 887-889.
- Yu Y and Cardona M (2001) Fundamentals of Semiconductors. 3rd ed., Springer, Berlin, Heidelberg.
- Investigations on Impact of Post-heat Temperature on Structural, Optical and Electrical Properties of Al-doped ZnO Thin Films Prepared by Sol-gel Method
Abstract Views :502 |
PDF Views:96
Authors
Affiliations
1 Dept. of Physics, Ferdowsi University of Mashhad, Mashhad, IR
1 Dept. of Physics, Ferdowsi University of Mashhad, Mashhad, IR
Source
Indian Journal of Science and Technology, Vol 3, No 2 (2010), Pagination: 110-112Abstract
Aluminum doped ZnO (AZO) thin films have been prepared by spin coating route on glass substrate. The structural, optical and electrical thin films have been characterized in different post-heat temperatures between 45° and 600°C. Xray diffraction analysis has revealed hexagonal wurtzite structure with (002) preferred orientation which increased in crystallite size by increasing post-heat temperature. The optical spectra of the films showed the transmittance higher than 90% within the visible wavelength region. Our results show that optical gap and surface resistance of the films are decreased by increasing post-heat temperature.Keywords
Sol-gel Method, Optical Spectra, Post-heat Temperature, Spin CoatingReferences
- Albrecht JD, Wang RP, Ruden PP and Brennan KF (1998) Monte Carlo simulation of GaN in zincblende and wurtzite structures. J. Appl. Phys. 83, 2185-2190.
- Bhuiyam S, Senoh M and Mukai T (2003) Comparison of steady state and transient electron Appl. Phys. Lett. 62, 2390-2395.
- Brennan K, Hess K, Tang JY and Iafrate GT (1983) High field electron transport properties. IEEE Trans.Elec. Devices. 30, 1750-1755.
- Fischetti MV and Laux SE (1991) Low field electron mobility in GaN. IEEE Trans. Elec. Devices. 38, 650- 655.
- Foutz BE, Eastman LE, Bhapkar UV and Shur M (1997) Full band Monte Carlo simulation of Zincblende GaN MESFET’s including realistic impact ionization rates. Appl. Phys. Lett. 70, 2849-2854.
- Ghani B, Hashimoto A and Yamamoto A (2003) High temperature characteristics of AlGaN/GaN modulation doped field-effect transistors. J. Appl. Phys. 94, 2779-2783.
- Izuka J and Fukuma M (1990) Full-band polar optical phonon scattering analysis and negative differential conductivity in wurtzite GaN. Solid-State Elec. 3, 27-33.
- Jacoboni J and Reggiani L (1983) The Monte Carlo simulation of Semiconductor and devices. Rev. Modern Phys. 55(3), 665-663.
- Kane EO (1957) Band structure calculation in group III and IV materials. J. Phys. Chem. Solids. 1, 249-253.
- Martienssen M and Warlimont H (2005) Springer hand book of condensed matter and materials data, Springer.
- The Effect of Deposition Parameters on the Sensing Behaviors of the SnO2: Cu Nano-structure Thin Films Including Co2-gas Sensor
Abstract Views :431 |
PDF Views:104
Authors
Affiliations
1 Physics Department, Ferdowsi University of Mashhad, Mashhad, IR
1 Physics Department, Ferdowsi University of Mashhad, Mashhad, IR
Source
Indian Journal of Science and Technology, Vol 3, No 6 (2010), Pagination: 627-629Abstract
In this work, Cu-doped SnO2 thin films were deposited by spray pyrolysis method. The films were prepared using SnCl4 ,5H2O and CuCl2,2H2O hydro-alcoholic solution. Then, the sensitivity parameter of SnO2-based CO2-gas sensors is studied for various atomic percentages ([Cu]/[Sn] = 0, 2, 4, 6, 10,12.5,15, 20, 25). In addition, the effect of substrate temperature on the sensing behavior of films was also studied. The XRD and SEM structural analysis of thin film sensors confirm the nano-structure of the films with SnO2 cassiterite phase. The optical band gap of Cu doped- SnO2 films were obtained from optical absorption spectra by UV-Vis absorption spectroscopy. Measurement of the electrical resistivity of films shows that with increasing of Cu-doping in films up to 12.5%, the electrical resistivity increase sharply.Keywords
Thin Film, Gas-sensors, Metal-oxide, Tin-oxide, NanostructureReferences
- Cao W, Tan OK , Zhu W, Jiang B and Reddy G (2001) A comprehensive review of ZnO materials and devices. Sensors Actuators B: Chem. 77, 421-426.
- Hooker SA (2002) Nanotechnology advantages applied to gas sensor development. Nanoparticles Conf.Proc. Business Commun. Co.
- Izu N, Shin W, Murayama N and Kanzaki M (2002) Resistive oxygen gas sensors based on CeO2 fine powder prepared using mist pyrolysis. Sensors Actuators B: Chem. 87, 95-98.
- Kissine V, Sysoeva V and Voroshilov S (2001) SnO2:Ga thin film as oxygen gas sensor. Sensors Actuators B: Chem. 7(9),163-170.
- Korotcenkov G, Brinzari B, Schwank G, Dibattis M and Vasiliev A (2001) Peculiarities of SnO2 thin film deposition by spray pyrolysis for gas sensor application. Sens. Actuators B. 77,144-252.
- Niranjan RS, Patil KR, Sankar SR and Mulla IS (2003) High H2S-sensitive copper-doped tin oxide thin film. Mater. Chem. Phys. 80, 250- 257.
- Xu Y, Zhou X and Sorensen T (2002) Oxygen sensors based on semiconducting metal oxides: an overview. Sensors Actuators B:Chem. 65, 2-4.
- Zhuiykov X, Wlodarski W and Li X (2001) Oxygen sensing prepared by sol–gel process. Sensors Actuators B: Chem. 77, 484-490.
- Steady-state and Transient Electron Transport within Bulk Ternary Nitride Semiconductors including Gainn, Algan and Alinn Using a Three-valley Monte Carlo Method
Abstract Views :582 |
PDF Views:116
Authors
Affiliations
1 Department of Physics, Ferdowsi University of Mashhad, Mashhad, IR
1 Department of Physics, Ferdowsi University of Mashhad, Mashhad, IR
Source
Indian Journal of Science and Technology, Vol 3, No 8 (2010), Pagination: 849-852Abstract
An ensemble Monte Carlo simulation is used to compare bulk electron transport in wurtzite phase GaInN, AlGaN and AlInN materials. Electronic states within the conduction band valleys at the Γ, U and K are represented by non-parabolic ellipsoidal valleys centered on important symmetry points of the Brillouin zone. For all materials it is found that electron velocity overshoot only occurs when the electric field is increased to a value above a certain critical field, unique to each material. This critical field is strongly dependent on the material parameters. Transient velocity overshoot has also been simulated with the sudden application of fields up to ~5×107 Vm-1, appropriate to the gate-drain fields expected within an operational field effect transistor. The electron drift velocity relaxes to the saturation value of ~1.5×105 ms-1 with in 4 ps for all crystal structures. The steady-state and transient velocity overshoot characteristics are in fair agreement with other recent calculations.Keywords
Brillouin Zone, Gate-drain, Transient, Critical Field, Drift Velocity, SemiconductorReferences
- Arabshahi H, Khalvati MR and Rezaee Rokn-Abadi M (2008) Monte Carlo modeling of hot electron transport in bulk AlAs, AlGaAs and GaAs at room temperature. Modern Phys. Lett. B, 22 (18), 1777-1784.
- Besikci B, Bakir M and Tanatar U (2000) Hot electron simulation devices. J. Appl. Phys. 88(3), 1243-1247.
- Bhapkar UV and Shur MS (1997) Ensemble Monte Carlo study of electron transport in wurtzite InN. J. Appl. Phys. 82, 1649-1654.
- Bhuiyam S, Senoh M and Mukai T (2003) Comparison of steady state and transient electron. Appl. Phys. Lett. 62, 2390-2395.
- Brennan K, Hess K, Tang JY and Iafrate GT (1983) High field electron transport properties. IEEE Trans. Elec. Dev. 30, 1750-1755.
- Fischetti MV and Laux SE (1991) Low field electron mobility in GaN. IEEE Trans. Elec. Dev. 38, 650-655.
- Foutz BE, Eastman LE, Bhapkar UV and Shur M (1997) Full band Monte Carlo simulation of Zincblende GaN MESFET’s including realistic impact ionization rates. Appl. Phys. Lett. 70, 2849-2854.
- Ghani B, Hashimoto A and Yamamoto A (2003) High temperature characteristics of AlGaN/GaN modulation doped field-effect transistors. J. Appl. Phys. 94, 2779-2783.
- Izuka J and Fukuma M (1990) Full-band polar optical phonon scattering analysis and negative differential conductivity in wurtzite GaN. Solid-State Elec. 3, 27-33.
- Jacoboni J and Lugli P (1989) The Monte Carlo method for semiconductor and device simulation. Springer-Verlag.
- Jacoboni J and Reggiani L (1983) The Monte Carlo simulation of semiconductor and devices. Rev. Modern Phys. 55(3), 665-663.
- Wang R P, Ruden P P, Kolnik J and Brennan K F (1997) Hot transport properties in group III nitrides. Mat. Res. Soc. Symp. Proc. 445, 935-941.
- Modeling of a 6H-SiC MESFET for High-power and High-gain Applications
Abstract Views :374 |
PDF Views:91
Authors
Affiliations
1 Physics Department, Ferdowsi University of Mashhad, Mashhad, IR
1 Physics Department, Ferdowsi University of Mashhad, Mashhad, IR
Source
Indian Journal of Science and Technology, Vol 4, No 1 (2011), Pagination: 1-3Abstract
A Monte Carlo simulation has been used to model steady state and transient electron transport in 6H-SiC field effect transistor. The simulated device geometries and doping are matched to the nominal parameters described for the experimental structures as closely as possible and the predicted I-V and transfer characteristics for the intrinsic devices show fair agreement with the available experimental data. Simulations of the effect of modulating the gate bias have also been carried out to test the device response and derived the frequency bandwidth. Value of 90±10 GHz has been derived for the intrinsic current gain cut-off frequency of the 6H-SiC MESFETs.Keywords
Steady-state, Transient, Cut-off Frequency, Frequency BandwidthReferences
- Albrecht JD, Ruden PP, Limpijumnong S, Lambrecht WRL and Brennan KF (1999) High field electron transport properties of bulk ZnO. J. Appl. Phys. 86, 6864-6867.
- Arabshahi H, Khalvati MR and Rezaee Rokn-Abadi M (2008) Comparison of steady-state and transient electron transport in InAs, InP AND GaAs. Modern Phys. Letts. B, 22(17), 1695-1702.
- Arabshahi H, Khalvati MR and Rezaee Rokn-Abadi M (2008) Temperature and doping dependencies of electron mobility in InAs, AlAs and AlGaAs at high electric field application. Braz. J. Phys. 38(3A), 293-296.
- Bhapkar UV and Shur MS (1997) Monte Carlo calculation of velocity-field characteristics of wurtzite GaN, J. Appl. Phys. 82, 1649-1655.
- Brennan KF (1998) Theory of high-field electronic transport in bulk ZnS and ZnSe. J. Appl. Phys. 64, 4024-4030.
- Brennan KF and Brown AS (2002) Theory of modern electronic semiconductor devices, John Wiley & Sons, Inc.
- Brennan KF, Belloti E, Farahmand M, Haralson J, Ruden PP, Albrecht JD and Sutandi A (2000) Materials theory based modeling of wide band gap semiconductors: From basic properties to devices. Solid-State elec. 44, 195-204.
- Donnarumma G, Wozny J and Lisik Z (2009) Monte Carlo simulation of bulk semiconductors for accurate calculation of drift velocity as a parameter for driftdiffusion,hydrodynamic models. Materials Sci. Engg. B, 165, 47-49.
- Farahmand M, Goano M and Ruden PP (2001) Monte Carlo simulation of electron transport in the III-nitride Wurtzite phase materials system: binaries and ternaries. IEE Trans. Elec. Dev. 48(3), 535-542.