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1.
Arsenic doped p-type ZnO thin films were grown on sapphire substrate by magnetron sputtering. As grown films reveal p-type conduction confirmed by Hall-effect and photoluminescence measurements. The p-type film with a hole concentration of 2.16× 1017 cm−3, mobility of 1.30 cm2/V.s and resistivity of 22.29 Ω-m were obtained at substrate temperature of 700 °C. ZnO homojunction synthesized by in-situ deposition of As doped p-ZnO layer on Al doped n-ZnO layer showed p-n diode like characteristics. X-ray pole figure and Transmission Electron Microscope studies confirm epitaxial nature of the films. Photoluminescence results exhibit the peaks associated with donor acceptor pair emission. 相似文献
2.
Optical and electrical characterization of well-aligned ZnO rods electrodeposited on stainless steel foil 总被引:1,自引:0,他引:1
A.E. Rakhshani 《Applied Physics A: Materials Science & Processing》2008,92(2):303-308
Aligned ZnO nanorods grown on polycrystalline substrates have promising optoelectronic applications. Novel samples with such
structures were electrodeposited on stainless steel foil from a ZnCl2 route. Well-aligned and free-standing hexagonal nanorods with 100-nm diameter and closely packed microrods with a diameter
above 1 μm could be grown normal to the substrate. The optical transition energies (absorption and emission) of samples were
determined by transmittance and photoluminescence spectroscopy. We report, for the first time, the fabrication of high-quality
Ag Schottky diodes formed on the oxygen-treated (002) facets of electrodeposited microrods. Diodes with a large barrier height
(1.2 eV), low saturation current density (1.3 pA/cm2) and high rectification factor (5×106 at ± 3 V) were achieved. The concentration and mobility of free electrons in oxygen-treated microrods were measured as 1.4×1014 cm-3 and 1.2 cm2 V-1 s-1, respectively.
PACS 81.15.Pq; 81.16.-c; 85.30.Kk; 81.05.Dz; 78.55.Et 相似文献
3.
H. Kim A. Cepler C. Cetina D. Knies M. S. Osofsky R. C. Y. Auyeung A. Piqué 《Applied Physics A: Materials Science & Processing》2008,93(3):593-598
Present p-type ZnO films tend to exhibit high resistivity and low carrier concentration, and they revert to their natural n-type state
within days after deposition. One approach to grow higher quality p-type ZnO is by codoping the ZnO during growth. This article describes recent results from the growth and characterization
of Zr–N codoped p-type ZnO thin films by pulsed laser deposition (PLD) on (0001) sapphire substrates. For this work, both N-doped and Zr–N
codoped p-type ZnO films were grown for comparison purposes at substrate temperatures ranging between 400 to 700 °C and N2O background pressures between 10−5 to 10−2 Torr. The carrier type and conduction were found to be very sensitive to substrate temperature and N2O deposition pressure. P-type conduction was observed for films grown at pressures between 10−3 to 10−2 Torr. The Zr–N codoped ZnO films grown at 550 °C in 1×10−3 Torr of N2O show p-type conduction behavior with a very low resistivity of 0.89 Ω-cm, a carrier concentration of 5.0×1018 cm−3, and a Hall mobility of 1.4 cm2 V−1 s−1. The structure, morphology and optical properties were also evaluated for both N-doped and Zr–N codoped ZnO films. 相似文献
4.
Chan y Díaz E. Duarte-Moller A. Camacho Juan M. Castro-Rodríguez R. 《Applied Physics A: Materials Science & Processing》2012,106(3):619-624
SnO2 thin films have been deposited on glass substrates by pulsed Nd:YAG laser at different oxygen pressures, and the effects
of oxygen pressure on the physical properties of SnO2 films have been investigated. The films were deposited at substrate temperature of 500°C in oxygen partial pressure between
5.0 and 125 mTorr. The thin films deposited between 5.0 to 50 mTorr showed evidence of diffraction peaks, but increasing the
oxygen pressure up to 100 mTorr, three diffraction peaks (110), (101) and (211) were observed containing the SnO2 tetragonal structure. The electrical resistivity was very sensitive to the oxygen pressure. At 100 mTorr the films showed
electrical resistivity of 4×10−2 Ω cm, free carrier density of 1.03×1019 cm−3, mobility of 10.26 cm2 V−1 s−1 with average visible transmittance of ∼87%, and optical band gap of 3.6 eV. 相似文献
5.
We report here an experimental study of the ionic keV X-ray line emission from magnesium plasma produced by laser pulses of
three widely different pulse durations (FWHM) of 45 fs, 25 ps and 3 ns, at a constant laser fluence of ∼1.5 × 104 J cm − 2. It is observed that the X-ray yield of the resonance lines from the higher ionization states such as H- and He-like ions
decreases on decreasing the laser pulse duration, even though the peak laser intensities of 3.5 × 1017 W cm − 2 for the 45 fs pulses and 6.2 × 1014 W cm − 2 for the 25 ps pulses are much higher than 5 × 1012 W cm − 2 for the 3 ns laser pulse. The results were explained in terms of the ionization equilibrium time for different ionization
states in the heated plasma. The study can be useful to make optimum choice of the laser pulse duration to produce short pulse
intense X-ray line emission from the plasma and to get the knowledge of the degree of ionization in the plasma. 相似文献
6.
A novel, simple, sensitive and selective spectrofluorimetric method was developed for the determination of trace amounts of
chlorzoxazone and Ibuprofen in pharmaceutical tablets using optical sensor Eu-Tetracycline HCl doped in sol–gel matrix. The
chlorzoxazone or Ibuprofen can remarkably enhance the luminescence intensity of Eu-Tetracycline HCl complex doped in a sol–gel
matrix in dimethylformamide (DMF) at pH 9.7 and 6.3, respectively, λex = 400 nm. The enhancing of luminescence intensity peak of Eu-Tetracycline HCl complex at 617 nm is proportional to the concentration
of chlorzoxazone or Ibuprofen a result that suggested profitable application as a simple optical sensor for chlorzoxazone
or Ibuprofen assessment. The dynamic ranges found for the determination of chlorzoxazone and Ibuprofen concentration are 5 × 10−9–1 × 10−4 and 1 × 10−8–7 × 10−5 mol L−1, and the limit of detection (LOD) and quantitation limit of detection (LOQ) are 3.1 × 10−10 , 9.6 × 10−10 and 5.6 × 10−10, 1.7 × 10−9 mol L−1, respectively. 相似文献
7.
Wang Bin Zhao Yue Min Jiahua Sang Wenbin 《Applied Physics A: Materials Science & Processing》2009,94(4):715-718
P-type ZnO was realized by dual-doping with nitrogen and silver via electrostatic-enhanced ultrasonic spray pyrolysis. The
structural, electrical, and optical properties were explored by XRD, Hall-effect, and optical transmission spectra. The resistivity
of ZnO:(N,Ag) film was found to be 56 Ω cm−1 with the high mobility of 76.1 cm2/V s. Compared with ZnO:Ag film, ZnO:(N,Ag) film exhibited a higher and more stable optical transmittance. 相似文献
8.
Ion-conducting thin film polymer electrolytes based on poly(ethylene oxide) (PEO) complexes with NaAlOSiO molecular sieves
powders has been prepared by solution casting technique. X-ray diffraction, scanning electron microscopy, differential scanning
calorimeter, and alternating current impedance techniques are employed to investigate the effect of NaAlOSiO molecular sieves
on the crystallization mechanism of PEO in composite polymer electrolyte. The experimental results show that NaAlOSiO powders
have great influence on the growth stage of PEO spherulites. PEO crystallization decrease and the amorphous region that the
lithium-ion transport is expanded by adding appropriate NaAlOSiO, which leads to drastic enhancement in the ionic conductivity
of the (PEO)16LiClO4 electrolyte. The ionic conductivity of (PEO)16LiClO4-12 wt.% NaAlOSiO achieves (2.370 ± 0.082) × 10−4 S · cm−1 at room temperature (18 °C). Without NaAlOSiO, the ionic conductivity has only (8.382 ± 0.927) × 10−6 S · cm−1, enhancing 2 orders of magnitude. Compared with inorganic oxide as filler, the addition of NaAlOSiO molecular sieves powders
can disperse homogeneously in the electrolyte matrix without forming any crystal phase and the growth stage of PEO spherulites
can be hindered more effectively. 相似文献
9.
Guoping Wang Sheng Chu Ning Zhan Huimei Zhou Jianlin Liu 《Applied Physics A: Materials Science & Processing》2011,103(4):951-954
P-type ZnO nanowires with silver (Ag) doping were synthesized via a chemical vapor deposition process. The incorporation of
Ag was confirmed by selected-area energy-dispersive x-ray spectroscopy. The formation of acceptor states was demonstrated
by temperature and excitation power-dependent photoluminescence measurements. Characterization of field-effect transistors
using Ag-doped ZnO nanowires as channels showed p-type conductivity of the nanowires with a hole concentration of 4.9×1017 cm−3 and a carrier mobility of approximately 0.18 cm2 V−1 s−1. 相似文献
10.
Deuk-Hee Lee Kyoungwon Kim Yoon Soo Chun Sangsig Kim Sang Yeol Lee 《Current Applied Physics》2012,12(6):1586-1590
High quality transparent conductive gallium-doped zinc oxide (GZO) thin films were deposited on glass substrates using rf-magnetron sputtering system at the temperature ranging from room temperature (RT) to 500 °C. The temperature-dependence of Ga doping effect on the structural, optical and electrical properties in ZnO has been investigated. For the GZO thin films deposited at over 200 °C, (103) orientation was strongly observed by X-ray diffraction analysis, which is attributed to the substitution of Ga elements into Zn site. X-ray photoelectron spectroscopy measurements have confirmed that oxygen vacancies were generated at the temperature higher than 300 °C. This might be due to the effective substitution of Ga3+ for Zn site at higher temperature. It was also found that the optical band gap increases with deposition temperature. The optical transmittance of GZO thin films was above 87% in the visible region. The GZO thin films grown at 500 °C showed a low electrical resistivity of 4.50 × 10?4 Ω cm, a carrier concentration of 6.38 × 1020 cm?3 and a carrier mobility of 21.69 cm2/V. 相似文献
11.
《Current Applied Physics》2015,15(5):588-598
Thin films of tin sulphide (SnS) have been grown by sulphurization of sputtered tin precursor layers in a closed chamber. The effect of sulphurization temperature (Ts) that varied in the range of 150–450 °C for a fixed sulphurization time of 120 min on SnS film was studied through various characterization techniques. X-ray photoelectron spectroscopy analysis demonstrated the transformation of metallic tin layers into SnS single phase for Ts between 300 °C and 350 °C. The X-ray diffraction measurements indicated that all the grown films had the (111) crystal plane as the preferred orientation and exhibited orthorhombic crystal structure. Raman analysis showed modes at 95 cm−1, 189 cm−1 and 218 cm−1 are related to the Ag mode of SnS. AFM images revealed a granular change in the grain growth with the increase of Ts. The optical energy band gap values were estimated using the transmittance spectra and found to be varied from 1.2 eV to 1.6 eV with Ts. The Hall effect measurements showed that all the films were p-type conducting nature and the layers grown at 350 °C showed a low electrical resistivity of 64 Ω-cm, a net carrier concentration of 2 × 1016 cm−3 and mobility of 41 cm2 V−1 s−1. With the use of sprayed Zn0.76Mg0.24O as a buffer layer and the sputtered ZnO:Al as window layer, the SnS based thin film solar cell was developed that showed a conversion efficiency of 2.02%. 相似文献
12.
N. Koteeswara Reddy K. Ramesh R. Ganesan K.T. Ramakrishna Reddy K.R. Gunasekhar E.S.R. Gopal 《Applied Physics A: Materials Science & Processing》2006,83(1):133-138
Tin sulphide films were grown at different substrate temperatures by a thermal co-evaporation technique. The crystallinity of the films was evaluated from X-ray diffraction studies. Single-phase SnS films showed a strong (040) orientation with an orthorhombic crystal structure and a grain size of 0.12 μm. The films showed an electrical resistivity of 6.1 Ω cm with an activation energy of 0.26 eV. These films exhibited an optical band gap of 1.37 eV and had a high optical absorption coefficient (>104 cm-1) above the band-gap energy. The results obtained were analysed to evaluate the potentiality of the co-evaporated SnS films as an absorber layer in solar photovoltaic devices. PACS 78.40.Fy; 68.60.-p; 61.10.Nz; 68.55.-a; 78.66.-w 相似文献
13.
A sequential three-dimensional (3D) particle-in-cell simulation code PICPSI-3D with a user friendly graphical user interface
(GUI) has been developed and used to study the interaction of plasma with ultrahigh intensity laser radiation. A case study
of laser–plasma-based electron acceleration has been carried out to assess the performance of this code. Simulations have
been performed for a Gaussian laser beam of peak intensity 5 × 1019 W/cm2 propagating through an underdense plasma of uniform density 1 × 1019 cm − 3, and for a Gaussian laser beam of peak intensity 1.5 × 1019 W/cm2 propagating through an underdense plasma of uniform density 3.5 × 1019 cm − 3. The electron energy spectrum has been evaluated at different time-steps during the propagation of the laser beam. When the
plasma density is 1 × 1019 cm − 3, simulations show that the electron energy spectrum forms a monoenergetic peak at ~14 MeV, with an energy spread of ±7 MeV.
On the other hand, when the plasma density is 3.5 × 1019 cm − 3, simulations show that the electron energy spectrum forms a monoenergetic peak at ~23 MeV, with an energy spread of ±7.5 MeV. 相似文献
14.
K. C. Cossel F. Adler K. A. Bertness M. J. Thorpe J. Feng M. W. Raynor J. Ye 《Applied physics. B, Lasers and optics》2010,100(4):917-924
Cavity-enhanced direct frequency comb spectroscopy (CE-DFCS) has demonstrated powerful potential for trace-gas detection based
on its unique combination of high bandwidth, rapid data acquisition, high sensitivity, and high resolution, which is unavailable
with conventional systems. However, previous demonstrations have been limited to proof-of-principle experiments or studies
of fundamental laboratory science. Here, we present the development of CE-DFCS towards an industrial application—measuring
impurities in arsine, an important process gas used in III–V semiconductor compound manufacturing. A strongly absorbing background
gas with an extremely complex, congested, and broadband spectrum renders trace detection exceptionally difficult, but the
capabilities of CE-DFCS overcome this challenge and make it possible to identify and quantify multiple spectral lines associated
with water impurities. Further, frequency combs allow easy access to new spectral regions via efficient nonlinear optical
processes. Here, we demonstrate detection of multiple potential impurities across 1.75–1.95 μm (5710–5130 cm−1), with a single-channel detection sensitivity (simultaneously over 2000 channels) of ∼4×10−8 cm−1 Hz−1/2 in nitrogen and, specifically, an absorption sensitivity of ∼4×10−7 cm−1 Hz−1/2 for trace water doped in arsine. 相似文献
15.
Y. W. Li Z. G. Hu F. Y. Yue W. Z. Zhou P. X. Yang J. H. Chu 《Applied Physics A: Materials Science & Processing》2009,95(3):721-725
(La0.5Sr0.5)CoO3 (LSCO) thin films have been fabricated on silicon substrate by the pulsed laser deposition method. The effects of substrate
temperature and post-annealing condition on the structural and electrical properties are investigated. The samples grown above
650°C are fully crystalline with perovskite structure. The film deposited at 700°C has columnar growth with electrical resistivity
of about 1.99×10−3 Ω cm. The amorphous films grown at 500°C were post-annealed at different conditions. The sample post-annealed at 700°C and
10−4 Pa has similar microstructure with the sample in situ grown at 700°C and 25 Pa. However, the electrical resistivity of the
post-annealed sample is one magnitude higher than that of the in situ grown sample because of the effect of oxygen vacancy.
The temperature dependence of resistivity exhibits semiconductor-like character. It was found that post-annealing by rapid
thermal process will result in film cracks due to the thermal stress. The results are referential for the applications of
LSCO in microelectronic devices. 相似文献
16.
Enrique Camps L. Escobar-Alarcón V. H. Castrejón-Sánchez P. Tolentino-Eslava 《Applied Physics A: Materials Science & Processing》2008,93(3):759-763
Amorphous carbon thin films were deposited by laser ablation of a graphite target, using the fundamental line of a 5 ns Nd:YAG
laser. Deposition was carried out as a function of the plasma parameters (mean kinetic ion energy and plasma density), determined
by means of a planar probe. In the selected working regimes the optical emission from the plasma is mainly due to atomic species,
namely C+ (426.5 nm); however, there is also emission from other atomic species and molecular carbon. The hardness and resistivity
could be varied in the range between 10 and 25 GPa, and 108 and 1011 Ω cm, respectively. The maximum values were obtained at a 200 eV ion energy and 6×1013 cm−3 plasma density, where the maximum quantity of C–C sp3 bonds was formed, as confirmed by Raman spectroscopy. 相似文献
17.
《Superlattices and Microstructures》2000,28(1):29-33
We report electrical and optical characteristics of a Si-doped (Al)GaInAs digital alloy/AlInAs Bragg mirror lattice matched to InP grown by molecular beam epitaxy. A 98.2% reflectivity with a 107 nm stop band width centred at 1.54 μ m is obtained. An average voltage drop of 16 mV per period at a current density of 1 KA cm − 2is observed for a mean electron concentration of about 5.5 × 1018cm − 3. The influence of structural and intrinsic properties of the heterostructure on the electrical resistivity and optical reflectivity is analysed. 相似文献
18.
Youssef AO 《Journal of fluorescence》2012,22(3):827-834
A new, simple, sensitive and selective spectrofluorimetric method for the determination of Hydrochlorothiazide was developed
in acetonitrile at pH 6.2. The Hydrochlorothiazide can remarkably enhance the luminescence intensity of the Tb3+ ion doped in sol–gel matrix at λex = 370 nm. The intensity of the emission band of Tb3+ ion doped in sol–gel matrix was increased due to the energy transfer from the triplet excited state of Hydrochlorothiazide
to (5D4) excited energy state of Tb3 ion. The enhancement of the emission band of Tb3+ ion doped in sol–gel matrix at (5D4→7 F5) 545 nm was directly proportion to the concentration of Hydrochlorothiazide with a dynamic ranges of 5.0 × 10−10—5.0 × 10−6 mol L−1 and detection limit of 2.2 × 10−11 mol L−1. 相似文献
19.
A. El Manouni F.J. Manjn M. Perales M. Mollar B. Marí M.C. Lopez J.R. Ramos Barrado 《Superlattices and Microstructures》2007,42(1-6):134
We report the effect of thermal annealing in air on the structural and optical properties of undoped and aluminium-doped (1%–4%) zinc oxide (AZO) thin films, grown by the spray pyrolysis technique on quartz substrates. Films were characterized by X-ray diffraction, low-temperature photoluminescence, electrical resistivity, and Raman spectroscopy after annealing at temperatures between 500 and 900 C. Annealing in air improves the long-range order crystalline quality of the bulk crystals, but promotes a number of point defects in the surface affecting both the resistivity and the photoluminescence. 相似文献
20.
Hybrid membranes doped with silicotungstic acid (STA) were prepared by sol–gel process with 3-glycidoxypropyltrimethoxysilane,
3-aminopropyltriethoxysilane, phosphoric acid, and tetraethoxysilane as chemical precursors. The thermogravimetry and differential
thermal analysis measurements confirmed that the hybrid membranes were thermally stable up to 350 °C. Relatively, a high proton
conductivity of 2.85 × 10−2 S/cm was obtained for 10 mol% STA-doped hybrid membrane at 120 °C under 90% RH. The hydrogen permeability was found to decrease
in the temperature range 20–120 °C from 1.64 × 10−10 to 1.36 × 10−10 mol/cm.s.Pa. 相似文献