Effect of annealing treatment on the structural, optical, and electrical properties of Al-doped ZnO thin films

Highly conductive and transparent Al-doped ZnO （AZO） thin films were prepared from a zinc target containing Al （1.5 wt.%） by direct current （DC） and radio frequency （RF） reactive magnetron sputtering. The structural, optical, and electrical properties of AZO films as-deposited and submitted to annealing treatment （at 300 and 400℃, respectively） were characterized using various techniques. The experimental results show that the properties of AZO thin films can be further improved by annealing treatment. The crystallinity of ZnO films improves after annealing treatment. The transmittances of the AZO thin films prepared by DC and RF reactive magnetron sputtering are up to 80% and 85% in the visible region, respectively. The electrical resistivity of AZO thin films prepared by DC reactive magnetron sputtering can be as low as 8.06 x 10-4 Ωcm after annealing treatment. It was also found that AZO thin films prepared by RF reactive magnetron sputtering have better structural and optical properties than that prepared by DC reactive magnetron sputtering.

Optical and electrical properties of TiO_2/Au/TiO_2 multilayer coatings in large area deposition at room temperature

TiO2/Au/TiO2 multilayer thin films were deposited at polymer substrate at room temperature using dc （direct current） magnetron sputtering method. By varying the thickness of each layer, the optical and electrical properties of the TiOz/Au/TiO2 multilayer films can be tailored to suit different applications. The thickness and optical properties of the Au layer and the quality of the Au-dielectric interfaces are critical for the electrical and optical performance of the Au-dielectric multilayer thin films. At the thickness of 8 rim, the Au layer forms a continuous structure having the lowest resistivity and it must be thin for high transmittance. The multilayer stack can be optimized to have a sheet resistance of 6 D./sq. at a transmittance over 80% at 680 nm in wavelength. The peak transmittance shifts towards the long wavelength region when the thickness of the two TiO2 （upper and lower） layers increases. When the film thickness of the two TiO2 film is 45 nm, a high transmittance value is obtained for the entire visible light wavelength region.

Structure distortion, optical and electrical properties of ZnO thin films co-doped with Al and Sb by sol-gel spin coating

ZnO thin films co-doped with A1 and Sb with different concentrations and a fixed molar ratio of AlCl3 to SbCl3 at 1：2, are prepared by a sol-gel spin-coating method on glass annealed at 550 ℃ for 2 h in air. The x-ray diffraction results confirm that the ZnO thin films co-doped with Al distortion, and the biaxial stresses are 1.03× 10^8. 3.26× 10^8 and Sb are of wurtzite hexagonal ZnO with a very small 5.23 × 10^8, and 6.97× 10^8 Pa, corresponding to those of the ZnO thin films co-doped with Al and Sb in concentrations of 1.5, 3.0, 4.5, 6.0 at% respectively. The optical properties reveal that the ZnO thin films co-doped with Al and Sb have obviously enhanced transmittance in the visible region. The electrical properties show that ZnO thin film co-doped with Al and Sb in a concentration of 1.5 at% has a lowest resistivity of 2.5 Ω·cm.

Comparisons of electrical and optical properties between graphene and silicene A review

Two-dimensional （2D） metamaterials are considered to be of enormous relevance to the progress of all exact sciences. Since the discovery of graphene, researchers have increasingly investigated in depth the details of electrical/optical proper- ties pertinent to other 2D metamaterials, including those relating to the silicene. In this review are included the details and comparisons of the atomic structures, energy diagram bands, substrates, charge densities, charge mobilities, conductivities, absorptions, electrical permittivities, dispersion relations of the wave vectors, and supported electromagnetic modes related to graphene and silicene. Hence, this review can help readers to acquire, recover or increase the necessary technological basis for the development of more specific studies on graphene and silicene.

Electrical and Optical Properties of GaSe Thin Films

The structure, electrical transport, and optical properties of GaSe films fabricated by means of radio-frequency (RF) magnetron sputtering in Ar were investigated. The as-sputtered GaSe films were amorphous, and their optical energy gap Eg are 1.9～2.6 eV. The effect of the synthesis conditions on the optical and electrical properties of the GaSe films has also been studied

Effect of compensation doping on the electrical and optical properties of mid-infrared type-II InAs/GaSb superlattice photodetectors

This paper presents a theoretical study on the electrical and optical properties of mid-infrared type-II InAs/GaSb superlattices with different beryllium concentrations in the InAs layer of the active region. Dark current, resistancearea product, absorption coefficient and quantum efficiency characteristics are thoroughly examined. The superlattice is residually n-type and it becomes slightly p-type by varying beryllium-doping concentrations, which improves its electrical performances. The optical performances remain almost unaffected with relatively low p-doping levels and begin to deteriorate with increasing p-doping density. To make a compromise between the electrical and optical performances, the photodetector with a doping concentration of 3 ×10^15 cm-3 in the active region is believed to have the best overall performances.

Structural, Optical and Electrical Properties of Evaporated CdSe Films

CdSe films are of great interest for use in thin film photoelectric devices. A simple chemical precipitation method is adopted for the first time to synthesise CdSe powder. Films on glass obtained at different substrate temperatures TS such as 300, 373, 423 and 473 K have been characterised by X-ray diffraction, optical absorption and Hall measurements.

Electrical and optical properties of Sb-doped ZnO thin films synthesized by sol–gel method

Sb-doped ZnO thin films with different values of Sb content （from 0 to 1.1 at.%） are deposited by the sol-gel dip- coating method under different sol concentrations. The effects of Sb-doping content, sol concentration, and annealing ambient on the structural, optical, and electrical properties of ZnO films are investigated. The results of the X-ray diffraction and ultraviolet-visible spectroscopy （UV-VIS） spectrophotometer indicate that each of all the films retains the wurtzite ZnO structure and possesses a preferred orientation along the c axis, with high transmittance （〉 90%） in the visible range. The Hall effect measurements show that the vacuum annealed thin films synthesized in the sol concentration of 0.75 mol/L each have an adjustable n-type electrical conductivity by varying Sb-doping density, and the photoluminescence （PL） spectra revealed that the defect emission （around 450 nm） is predominant. However, the thin films prepared by the sol with a concentration of 0.25 mol/L, despite their poor conductivity, have priority in ultraviolet emission, and the PL peak position shows first a blue-shift and then a red-shift with the increase of the Sb doping content.

Effects of preparation parameters on growth and properties of β-Ga_(2)O_(3) film

The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and annealing temperature)on the growth and properties(e.g., surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer(XRD), scanning electron microscope(SEM), and ultraviolet-visible spectrophotometer(UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the β-Ga_(2)O_(3) film are influenced by those parameters. All β-Ga_(2)O_(3) films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The I–V curves show that the Ohmic behavior between metal and β-Ga_(2)O_(3) films is obtained at 900℃. Those results will be helpful for the further research of β-Ga_(2)O_(3) photoelectric semiconductor.

MLCROSTRUCTURE AND PROPERTIES OF C-Cu NANOSTRUCTURE THIN FILM

Nanostructured C-Cu thin films were deposited by reactive sputtering method and cosputtering method. The relationships between microstructures, properties, and deposition parameters were studied and the results obtained from TEM, AFM, and XPS. indicate that the thin films are nanostructural, and have good in-depth uniformity. The selected area electron diffraction (SAED) found that the nanosize Cu particles have the fcc structure and the others are amorphous carbon or nanocrystallized graphitic carbon. The peak positions of the Cu and C in XPS indicate them to be at the elemental state. In the JR transmission spectrum, diamond two-phonon absorption and graphite Reman peaks were observed, which suggests microcrystal diamond particles and graphite components exrist in the C-Cu film. The higher electrical resistivity was obtained.

Effect of the Sputtering Parameters on the Structure and Properties of Cu_3N Thin Film Materials

Copper nitride （Cu3N） thin films were successfully deposited on glass substrates by reactive radio frequency magnetron sputtering.The effects of sputtering parameters on the structure and properties of the films were studied.The experimental results show that with increasing of RF power and nitrogen partial pressure,the preferential crystalline orientation of Cu3N film is changed from （111） to （100）.With increasing of substrate temperature from 70 ℃ to 200 ℃,the film phase is changed from Cu3N phase to Cu.With increasing sputtering power from 80 W to 120 W,the optical energy decreases from 1.85 eV to 1.41 eV while the electrical resistivity increases from 1.45 ×102 Ω·cm to 2.99×103 Ω·cm,respectively.

Effect of Oxygen Partial Pressure on Epitaxial Growth and Properties of Laser-Ablated AZO Thin Films

Al-doped ZnO（AZO） thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures（P_（O2））.The effect of P_（O2） on the crystal structure,preferred orientation as well as the electrical and optical properties of the films was investigated.The structure characterizations indicated that the as-grown films were single-phased with a wurtzite ZnO structure,showing a significant c-axis orientation.The films were well crystallized and exhibited better crystallinity and denser texture when deposited at higher P_（O2）.At the optimum oxygen partial pressures of 10- 15 Pa,the AZO thin films were epitaxially grown on c-sapphire substrates with the（0001） plane parallel to the substrate surface,i e,the epitaxial relationship was AZO（000 1） // A1_2O_3（000 1）.With increasing P_（O2）,the value of Hall carrier mobility was increased remarkably while that of carrier concentration was decreased slightly,which led to an enhancement in electrical conductivity of the AZO thin films.All the films were highly transparent with an optical transmittance higher than 85%.

Reply to Comments on "Structural,Optical,and Electrical Properties of Zn-Doped CdO Thin Films Fabricated by a Simplified Spray Pyrolysis Technique'' by K.Usharani and A.R.Balu published in Acta Metall.Sin.(Engl.Lett.) 28(1),64–71(2015)

Following are the comments for the queries raised by Prof. Pawel E. Tomaszewski on our published paper entitled ＂Structural, Optical, and Electrical Properties of Zn-Doped CdO Thin Films Fabricated by a Simplified Spray Pyrolysis Technique＂ by K. Usharani and A.R. Balu published in Acta Metall. Sin.

Correlation between the structural, morphological, optical, and electrical properties of In_2O_3 thin films obtained by an ultrasonic spray CVD process

Indium oxide （In2O3） thin films are successfully times by an ultrasonic spray technique using Indium chloride deposited on glass substrate at different deposition as the precursor solution; the physical properties of these films are characterized by XRD, SEM, and UV-visible. XRD analysis showed that the films are polycrys- talline in nature having a cubic crystal structure and symmetry space group Ia3 with a preferred grain orientation along the （222） plane when the deposition time changes from 4 to 10 min, but when the deposition time equals 13 min we found that the majority of grains preferred the （400） plane. The surface morphology of the In2O3 thin films revealed that the shape of grains changes with the change of the preferential growth orientation. The trans- mittance improvement of In2O3 films was closely related to the good crystalline quality of the films. The optical gap energy is found to increase from 3.46 to 3.79 eV with the increasing of deposition time from 4 to 13 min. The film thickness was varied between 395 and 725 nm. The film grown at 13 min is found to exhibit low resistivity （10-2 Ω.cm）, and relatively high transmittance （- 93%）.

Comments on "Structural,Optical,and Electrical Properties of Zn-Doped CdO Thin Films Fabricated by a Simplified Spray Pyrolysis Technique'' by K.Usharani and A.R.Balu Published in Acta Metall.Sin.(Engl.Lett.) 28(1),64–71(2015)

The commented paper [1] presents the results on structural, optical, and electrical properties of Zn-doped CdO thin films. Unfortunately, there are several mistakes and errors not found by any of referees. It is necessary to show these mistakes or misleading statements to avoid their use in the future papers by authors and other peoples.

Structural, optical and electrical properties of Sn_xS_y thin films grown by spray ultrasonic

Tin sulfide（Snx Sy/ thin films were prepared by a spray ultrasonic technique on glass substrate at 300℃.The influence of deposition time tD2, 4, 6, 8 and 10 min on different properties of thin films, such as（XRD）,photoluminescence（PL） and（UV） spectroscopy visible spectrum and four-point were investigated. X-ray diffraction showed that thin films crystallized in SnS2, SnS, and Sn2S3 phases, but the most prominent one is SnS_2. The results of the（UV） spectroscopy visible spectrum show that the film which was deposited at 4 min has a large transmittance of 60% in the visible region. The photoluminescence spectra exhibited the luminescent peaks in the visible region, which shows its potential application in photovoltaic devices. The electrical resistivity（ρ） values of SnxSy films have changed from 8.1×1064to 1.62Ω·cm with deposition time.

Preparation of AZO Nanoparticles, Ceramic Targets and Thin Films by a Co-precipitaition Method

We comprehensively study the co-precipitation preparation of aluminum doped zinc oxide（AZO） nanoparticles, ceramic target and thin fi lm deposition. The nanoparticles calcined below 700 ℃ possessed pure wurtzite structure of ZnO. When the calcination temperature exceeded 700 ℃, ZnAl2O4 phase appeared. The resistivity and relative density of the AZO target pressed from nanoparticles were 3×10^-3 Ω·cm and 99.1%, respectively. The minimum resistivity of AZO thin films prepared by DC sputtering of the ceramic target reached 4.1×10^-4Ω·cm with the mobility of 33 cm^2/v·s and the carrier concentration of 4.5 ×10^20 cm^-3. The average optical transmittance of the AZO thin films in the visible wavelength range（400-800 nm） was more than 80%.

Studies on morphology, electrical and optical characteristics of Al-doped ZnO thin films grown by atomic layer deposition

Al doped ZnO（AZO） films deposited on glass substrates through the atomic layer deposition（ALD）technique are investigated with various temperatures from 100 to 250 °C and different Zn ： Al cycle ratios from20 ： 0 to 20 ： 3. Surface morphology, structure, optical and electrical properties of obtained AZO films are studied in detail. The Al composition of the AZO films is varied by controlling the ratio of Zn ： Al. We achieve an excellent AZO thin film with a resistivity of 2.14 × 10^（-3）Ω·cm and high optical transmittance deposited at 150 °C with20 ： 2 Zn ： Al cycle ratio. This kind of AZO thin films exhibit great potential for optoelectronics device application.