Sb Doping Concentration Research Articles

Sb-related defects in Sb-doped ZnO thin film grown by pulsed laser deposition

Sb-doped ZnO films were fabricated on c-plane sapphire using the pulsed laser deposition method and characterized by Hall effect measurement, X-ray photoelectron spectroscopy, X-ray diffraction, photoluminescence, and positron annihilation spectroscopy. Systematic studies on the growth conditions with different Sb composition, oxygen pressure, and post-growth annealing were conducted. If the Sb doping concentration is lower than the threshold ∼8 × 1020 cm−3, the as-grown films grown with an appropriate oxygen pressure could be n∼4 × 1020 cm−3. The shallow donor was attributed to the SbZn related defect. Annealing these samples led to the formation of the SbZn-2VZn shallow acceptor which subsequently compensated for the free carrier. For samples with Sb concentration exceeding the threshold, the yielded as-grown samples were highly resistive. X-ray diffraction results showed that the Sb dopant occupied the O site rather than the Zn site as the Sb doping exceeded the threshold, whereas the SbO related deep acceptor was responsible for the high resistivity of the samples.

High-throughput combinatorial chemical bath deposition: The case of doping Cu (In, Ga) Se film with antimony

The conventional methods for designing and preparing thin film based on wet process remain a challenge due to disadvantages such as time-consuming and ineffective, which hinders the development of novel materials. Herein, we present a high-throughput combinatorial technique for continuous thin film preparation relied on chemical bath deposition (CBD). The method is ideally used to prepare high-throughput combinatorial material library with low decomposition temperatures and high water- or oxygen-sensitivity at relatively high-temperature. To check this system, a Cu(In, Ga)Se (CIGS) thin films library doped with 0–19.04 at.% of antimony (Sb) was taken as an example to evaluate the regulation of varying Sb doping concentration on the grain growth, structure, morphology and electrical properties of CIGS thin film systemically. Combined with the Energy Dispersive Spectrometer (EDS), X-ray Photoelectron Spectroscopy (XPS), automated X-ray Diffraction (XRD) for rapid screening and Localized Electrochemical Impedance Spectroscopy (LEIS), it was confirmed that this combinatorial high-throughput system could be used to identify the composition with the optimal grain orientation growth, microstructure and electrical properties systematically, through accurately monitoring the doping content and material composition. According to the characterization results, a Sb2Se3 quasi-liquid phase promoted CIGS film-growth model has been put forward. In addition to CIGS thin film reported here, the combinatorial CBD also could be applied to the high-throughput screening of other sulfide thin film material systems.

First-principles investigation of the effects of Sb doping on the LiNiO2

First-principles calculations have been carried out to investigate the effects of Sb doping on the LiNiO2. It is found that crystal lattice parameters of the Sb-doped LiNiO2 increase with the increasing doping concentration of Sb. In order to properly assess the difficulty of Sb doping in the LiNiO2, the formation energies of SbxNi12−xO24(x=1,2,3) are firstly obtained according to the elemental chemical potentials determined by the phase stability conditions. Calculated formation energies indicate that the growth conditions of Sb2O5-rich, O-rich and Ni-rich contribute to the formation of SbxNi12−xO24(x=1,2,3). Furthermore, Sb1Ni11O24, Sb2Ni10O24 and Sb3Ni9O24 all have good thermodynamic stability if their growth conditions are reasonably adjusted. Besides, among Li12Ni12O24, Li12SbNi11O24, Li12Sb2Ni10O24 and Li12Sb3Ni9O24, Li12Sb2Ni10O24 has the smallest ratio of volume change and the highest theoretical average intercalation voltage during Li ion lithiation/delithiation process. Therefore, electronic structures of Li12Ni12O24 and Li12Sb2Ni10O24 are further analyzed. The calculated results demonstrate that Li12Sb2Ni10O24 has better stability and conductivity than Li12Ni12O24. Moreover, in the Li12Sb2Ni10O24, the electrostatic interaction between Li+ and Ni-O layers reduces compared with LiNiO2, which suggests that the diffusion ability of Li can be improved by Sb doping. Moreover, Li12Sb2Ni10O24 has better electrochemical properties than LiNiO2.

Structural, morphological, electrical and optical properties of SnO2 nanoparticles: influence of Sb doping

Sb doped SnO2 (ATO) nanoparticles with Sb doping concentrations ranging from 0 to 20 % were prepared by coprecipitation method. The average crystal size of the ATO nanoparticles decreased from 11 to 3.5 nm by increasing the Sb doping concentration. The ATO nanoparticles doped with 20 % Sb doping concentration displayed preferred (110) exposed crystal planes. The electrical resistivity of ATO nanoparticles decreased from 9.47 kΩ cm to minimum of 14.85 Ω cm when Sb doping concentration increased from 0 to 10 % and then increased to 90.79 Ω cm when Sb doping concentration increased to 20 %. The optical band gap of ATO nanoparticles was either increased or decreased, strongly depending on the Sb doping concentration.

Effect of Sb doping on the structural, electrical, and optical properties of SnO2 thin films prepared through spray pyrolysis

In this research, antimony-doped tin dioxide (ATO) films were deposited on glass substrates at T = 550 °C through spray pyrolysis. The effects of antimony doping on the structural, optical, and electrical properties of the thin films were investigated. Tin chloride (SnCl4·5H2O) and antimony chloride (SbCl3) were used as a host and a dopant precursor, respectively. X-ray diffraction (XRD) analysis indicated that the undoped SnO2 thin film exhibited a preferred (211) orientation. As the Sb doping concentration increased, a different preferred (200) orientation was observed. Field emission scanning electron microscopy analysis revealed polyhedron-like grains of the thin films. Atomic force microscopy analysis demonstrated that the minimum and maximum amounts of roughness were within the \(\frac{{\left[ {Sb} \right]}}{{\left[ {Sn} \right]}}\%\) molar ratio of 10 and 7.5 at.% concentrations, respectively. As the doping concentration increased, the average grain size initially increased and then decreased; electrical resistance initially decreased and subsequently increased; the carrier concentration and Hall mobility initially increased and then decreased; and Seebeck coefficient decreased. The optical band gap of the thin films ranged from 3.16 to 3.8 eV. Hall effect and thermoelectric studies revealed that the films exhibited an n-type conductivity.

PVP-Assisted Sb-Doped SnO<sub>2</sub> Nanofibers Synthesized by Electrospinning Process

Well-defined Sb-doped tin oxide (ATO) nanofibers were synthesized by electrospinning technique. Polyvinylpyrrolidone (PVP), SnCl4·5H2O and SbCl3 were chosen as suitable precursors for preparing ATO nanofibers. All of precursors were homogeneously dissolved with the mixture solvent of dimethylformamide (DMF) and absolute ethanol. Electrospinning process was carried out at applied voltage of 10 kV and distance between needle tip to aluminium foil collector was fixed at 10 cm. The injection rate of precursor solution was controlled at 0.5 ml/hr. The as-spun nanofibers were calcined at 600°C with heating rate of 5 °C/min in order to remove the PVP template and improve the crystallinity of ATO structure. Effect of Sb doping concentration on their crystal structure was investigated. The morphology and crystal structure of the electrospun fibers were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). In this work, the obtained ATO nanofibers had average range diameter from 150 to 350 nm with rough surface. Sb doping concentration in ATO nanofibers plays a key role on their network morphology. The excellent doping concentration of Sb that offered the continuous fibrous and porous ATO nanofibers was 7%.

Hall and Seebeck measurements estimate the thickness of a (buried) carrier system: Identifying interface electrons in In-doped SnO2 films

We propose a simple method based on the combination of Hall and Seebeck measurements to estimate the thickness of a carrier system within a semiconductor film. As an example, this method can distinguish “bulk” carriers, with homogeneous depth distribution, from “sheet” carriers, that are accumulated within a thin layer. The thickness of the carrier system is calculated as the ratio of the integral sheet carrier concentration, extracted from Hall measurements, to the volume carrier concentration, derived from the measured Seebeck coefficient of the same sample. For rutile SnO2, the necessary relation of Seebeck coefficient to volume electron concentration in the range of 3 × 1017 to 3 × 1020 cm−3 has been experimentally obtained from a set of single crystalline thin films doped with varying Sb-doping concentrations and unintentionally doped bulk samples, and is given as a “calibration curve.” Using this calibration curve, our method demonstrates the presence of interface electrons in homogeneously deep-acceptor (In) doped SnO2 films on sapphire substrates.

Low temperature fabrication and doping concentration analysis of Au/Sb ohmic contacts ton-type Si

This paper investigates low temperature ohmic contact formation of Au/Sb to n-type Si substrates through AuSb/NiCr/Au metal stacks. Liquid epitaxy growth is utilized to incorporate Sb dopants into Si substrate in AuSi melt. The best specific contact resistivity achieved is 0.003 Ω ⋅ cm2 at 425 oC. Scanning electron microscopy (SEM) reveals inverted pyramidal crater regions at the metal/semiconductor interface, indicating that AuSi alloying efficiently occurs at such sites. Secondary ion mass spectroscopy (SIMS) shows that Sb atoms are successfully incorporated into Si as doping impurities during the anneal process, and the Sb doping concentration at the contact interface is found to be higher than the solid solubility limit in a Si crystal. This ohmic contacts formation method is suitable for semiconductor fabrication processes with limited thermal budget, such as post CMOS integration of MEMS.

Optical Property of Sb-Doped SnO<sub>2</sub> Nanoparticle Thin Films by Sparking Process

Undoped and Sb doped SnO2 nanoparticle thin films were synthesized by sparking process. The nanoparticles were continuously deposited onto the substrate by varying the number of sparking cycles ranging from 10-30 and the deposited film were subsequently annealed at 500 °C in tube furnace under air atmosphere for 1 h. The effect of Sb doped SnO2 nanoparticles thin film on their structure and optical characteristics were investigated. The optical properties of the nanoparticles thin films have been studied from transmission spectra. An average transmittance of the thin films decrease from 70% to 50% when the doping level increased from 0 to 7 %Sb doped SnO2. Opitical band gap energy of thin films were found to vary in range of 3.85-3.89 eV which the energy band gap decrease with the increasing Sb doping concentration. From the experimental data, the reduction of optical transmittance spectra in the antimony doped SnO2 thin films make it suitable for generation of window layer coating and prevent unwanted absorption in UV range.

Sb-Doped SnO2 Nanoparticles Synthesized by Sonochemical-Assisted Precipitation Process.

Sb-doped SnO2 nanopowders were synthesized by sonochemical-assisted precipitation process using stannic chloride pentahydrate (SnCl4.5H2O) and antimony chloride (SbC3) as starting precursors. Effect of sonication and Sb doping concentrations on physical structures and electrical properties of Sb-doped SnO2 nanoparticles were investigated by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Raman spectroscopy and two-point probe method. The results indicated that the good dispersion with less agglomeration of particles in SnO2 phase can be obtained by single step sonochemical-assisted process. Moreover, XRD results indicated that the crystallinity of Sb-doped SnO2 nanopowders deteriorated with increasing Sb content, suggesting that Sb dopant significantly prevent SnO2 crystallite growth. The XPS spectra of Sb-doped SnO2 obviously confirmed the existence of Sb ion incorporated into SnO2 matrix. These results revealed that incorporation of Sb ions into SnO2 lattice with specific concentration has significant influence on formation and crystallization and can dramatically enhance the conductivity of tin oxide.

White Light‐Emitting Diode From Sb‐Doped p‐ZnO Nanowire Arrays/n‐GaN Film

A whole interfacial transition of electrons from conduction bands of n‐type material to the acceptor levels of p‐type material makes the energy band engineering successful. It tunes intrinsic ZnO UV emission to UV‐free and warm white light‐emitting diode (W‐LED) emission with color coordinates around (0.418, 0.429) at the bias of 8–15.5 V. The W‐LED is fabricated based on antimony (Sb) doped p‐ZnO nanowire arrays/Si doped n‐GaN film heterojunction structure through one‐step chemical vapor deposition with quenching process. Element analysis shows that the doping concentration of Sb is ≈1.0%. The I–V test exhibits the formation of p‐type ZnO nanowires, and the temperature‐dependent photoluminescence measurement down to 4.65 K confirms the formation of deep levels and shallow acceptor levels after Sb‐doping. The intrinsic UV emission of ZnO at room temperature is cut off in electroluminescence emission at a bias of 4–15.5 V. The UV‐free and warm W‐LED have great potential application in green lights program, especially in eye‐protected lamp and display since television, computer, smart phone, and mobile digital equipment are widely and heavily used in modern human life, as more than 3000 h per year.

Structural, morphological, optical and electrical properties of spray-deposited Sb-doped WO3 nanocrystalline thin films prepared using ammonium tungstate precursor

Spray-deposited Sb-doped WO3 thin films have been investigated using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray system, and atomic force microscopy (AFM) in order to study structural and morphological properties of the films. The XRD and Raman studies confirm the monoclinic phase of WO3 with preferred orientation along the (200) plane. The SEM and AFM analyses show that with the increase of Sb-doping concentration, the surface becomes more and more compact, and the surface roughness increases. Both the direct and indirect band gap energies have been found to decrease upon Sb doping. PL emission spectra show two major peaks—one blue emission at 424 nm and another green emission at 500 nm. The electrical studies reveal that the room temperature resistivity decreases with the increasing Sb doping concentration.

Fabrications of different Sb content p-SnO2 thin films

Tin oxide (SnO2) is a wide-band-gap semiconductor with a bandwidth of 3.6 eV at room temperature, which is widely used in many fields, such as gas sensors, transparent electrodes and optoelectronic devices due to its high optical transparency, low resistivity, and higher chemical and physical stability. However for the real applications of SnO2 based optoelectronic devices, it is necessary to obtain both n-type and p-type SnO2 materials. Unfortunately, SnO2 is intrinsically an n-type semiconductor material, therefore most efforts have been made to obtain p-type SnO2 materials. In this paper, SnO2 thin films with different Sb12 concentrations are grown on Al2O3 substrates by chemical vapor deposition method through using Sb2O3 and SnO as reaction source. The surface morphology, elemental concentration, and structural properties of SnO2 thin films with different Sb concentrations are investigated by field-emission scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction, respectively. As the Sb content increases, the SnO2 thin films become more smooth and the grain size increases, indicating that the crystal quality of the thin film is improved. It is also found small amount of Sb doping of SnO2 thin film can be act as a surfactant. Moreover, the Hall measurement results indicate that the Sb doped SnO2 thin film has a p-type conductivity for an optimum Sb2O3/SnO mass ratio of 1:5. The optical absorption spectrum measurement indicates that the energy gap of sample is evidently blue-shifted with increasing Sb doping concentration. Furthermore, the Sb doped p-SnO2/n-SnO2 thin film homojunction is successfully fabricated to verify the p-type conductivity of Sb doped SnO2. The Sb doped p-SnO2/n-SnO2 homojunction device shows good rectifier characteristics, and its forward-turn-on voltage is 3.4 V.

Effect of antimony doping on the structural, optical and electrical properties of SnO2 thin films prepared by spray ultrasonic

Antimony doped tin oxide (ATO) or (SnO2:Sb) thin films have been prepared by spray ultrasonic on heated glass substrates at 480°C for 3min as time deposition. The dependence of structural, optical and electrical properties of SnO2:Sb films on the Sb concentration (0–1wt.%), is investigated. X-ray diffraction pattern reveals the presence of cassiterite structure with (211) as preferred orientation for ATO films with presence of other orientations. Focused analysis, on (211) peaks, indicated that the interplanar spacing of SnO2 (211) increases, after Sb doping until 0.8wt.% level, due to the substitution of some Sn+4 by some Sb in Sb+3 state, (Sbsub), into the SnO2 lattice, causing distortion and generated oxygen vacancies. Good agreement has been found between AFM topographical images of the SnO2:Sb samples and XRD grain size measurements. The crystallite size varies from 24.93 to 33.25nm and was affected by Sb concentration whereas the lattice parameters (a and c) are found to increase with Sb doping concentration until 0.8wt.% level and then decrease. Transparency in the visible range was around ∼80%. At Sb doping level lower than 0.8wt.%, all the envelope of transmission T(λ) curves become contracted and shift toward lower wavelength revealing the effect of plasma carrier concentration in absorbing light. The optical band gap (Eg) increases from 3.65 to 3.92eV and then decreases. Minimum resistance sheet (Rsh) and maximum carrier concentration n achieved for SnO2:Sb thin films have been found to be 31.07Ωcm2 and 11.8 10+19cm−3 at 0.8wt.% Sb doping level.

Enhanced separation efficiency of photoinduced charges for antimony-doped tin oxide (Sb-SnO2)/TiO2 heterojunction semiconductors with varied Sb doping concentration

In this paper, antimony-doped tin oxide (Sb-SnO2) nanoparticles were synthesized with varied Sb doping concentration, and the Sb-SnO2/TiO2 heterojunction semiconductors were prepared with Sb-SnO2 and TiO2. The separation efficiency of photoinduced charges was characterized with surface photovoltage (SPV) technique. Compared with Sb-SnO2 and TiO2, Sb-SnO2/TiO2 presents an enhanced separation efficiency of photoinduced charges, and the SPV enhancements were estimated to be 1.40, 1.43, and 1.99 for Sb-SnO2/TiO2 composed of Sb-SnO2 with the Sb doping concentration of 5%, 10%, and 15%, respectively. To understand the enhancement, the band structure of Sb-SnO2 and TiO2 in the heterojunction semiconductor was determined, and the conduction band offsets (CBO) between Sb-SnO2 and TiO2 were estimated to be 0.56, 0.64, and 0.98 eV for Sb-SnO2/TiO2 composed of Sb-SnO2 with the Sb doping concentration of 5%, 10%, and 15%, respectively. These results indicate that the separation efficiency enhancement is resulting from the energy level matching, and the increase of enhancement is due to the rising of CBO.

Influence of Sb doping on the structural, optical and electrical properties of p-ZnO thin films prepared on n-GaN/Al2O3 substrates by a simple CVD method

ZnO thin films with different Sb doping concentrations were prepared on n-GaN/Al2O3 substrates by simple chemical vapor deposition. Field-emission scanning electron microscopy (FE-SEM) showed that the morphologies of ZnO thin films were rougher and the size of the crystal grains reduced with increasing Sb concentration. The X-ray diffraction measurements indicated that the (002) diffraction peak positions of samples shifted gradually towards the lower angle side, which explained the substitution of Sb3+ into the Zn site by Sb doping. In addition, Hall measurement results indicated that Sb doped ZnO thin films had p-type conductivity, and the optimal Sb2O3/ZnO mass ratio for p-type ZnO thin film was approximately 1:4. Optical absorption spectrum measurement indicated that the energy gaps of the samples were evidently narrowed with increasing Sb doping concentration.

Compositional effect of antimony on structural, optical, and photoluminescence properties of chemically deposited (Cd1−xSbx)S thin films

(Cd1−xSbx)S thin films were deposited onto glass substrates by the chemical bath deposition. Systematic studies have been undertaken to investigate the effect of Sb composition on thin film properties of chemically deposited (Cd1−xSbx)S thin films. The films were characterized by using X-ray diffractometer (XRD), atomic force microscopy (AFM), photoluminescence emission spectra and UV–VIS–NIR spectrophotometer. The XRD patterns reveal that these thin films have mixed phase of cubic CdS and orthorhombic Sb2S3 crystal structure. AFM images showed uniform deposition of the material over the entire glass substrate and rms roughness was also calculated. The energy band gap for thin films were revealed from the optical studies and were found to decrease from 2.41eV to 2.20eV with increasing Sb doping concentration. After annealing at 400°C, the band gap is found to be increased in the range 2.51–2.26eV. The photoluminescence emission spectra of the films shows two luminescence bands centered around 420nm and 510nm under 250nm excitation.

Microstructure and physical properties of sol gel derived SnO2:Sb thin films for optoelectronic applications

Antimony doped tin oxide thin films were deposited on glass substrates by sol-gel dip coating technique. X-ray diffraction pattern showed the deterioration of the crystallinity of the films with increase in antimony doping concentration. Atomic force microscopy studies showed an inhibition of grain growth with increase in Sb concentration.The rms roughness value of SnO2:Sb thin films are found to 1% of film thickness which makes them suitable for optoelectronic applications. The film surface revealed positive skewness and high kurtosis values which make them favorable for tribological applications. The lowest resistivity (about10−5Ωm) was obtained for the 5mol% Sb doped SnO2: Sb films. These films acquire n-type conductivity due to non- stoichiometry (oxygen vacancies and interstitial tin atoms) and by the addition of Sb. The optical properties of the films have been studied from transmission spectra. An average transmittance of >80% (in UV–vis region) was observed for all the films. Optical band gap energy of SnO2:Sb films were found to vary in the range of 3.69–3.97eV with the increase in Sb doping concentration. Photoluminescence spectra of the films exhibited an increase in the emission intensity with increase in antimony doping concentration which is due the combined effect of charge balance and decrease in grain size. The enhancement of PL intensity in the antimony doped SnO2 thin films make it suitable for generation of solid state lighting in light emitting diode.

Epitaxial growth of Sb-doped nonpolar a-plane ZnO thin films on r-plane sapphire substrates by RF magnetron sputtering

► Sb-doped nonpolar a -plane ZnO layers were epitaxially grown on sapphire substrates. ► Crystallinity and electrical properties were studied upon growth condition and doping concentration. ► The out-of-plane lattice spacing of ZnO films reduces monotonically with increasing Sb doping level. ► The p-type conductivity of ZnO:Sb film is closely correlated with annealing condition and Sb doping level. In this study, the epitaxial growth of Sb-doped nonpolar a -plane ( 1 1 2 ¯ 0 ) ZnO thin films on r -plane ( 1 1 ¯ 0 2 ) sapphire substrates was performed by radio-frequency magnetron sputtering. The influence of the sputter deposition conditions and Sb doping concentration on the microstructural and electrical properties of Sb-doped ZnO epitaxial films was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and the Hall-effect measurement. The measurement of the XRD phi-scan indicated that the epitaxial relationship between the ZnO:Sb layer and sapphire substrate was 1 1 2 ¯ 0 ZnO / / ( 1 1 ¯ 0 2 ) Al 2 O 3 and 1 1 ¯ 0 0 ZnO / / 1 1 2 ¯ 0 Al 2 O 3 . The out-of-plane a -axis lattice parameter of ZnO films was reduced monotonically with the increasing Sb doping level. The cross-sectional transmission electron microscopy (XTEM) observation confirmed the absence of any significant antimony oxide phase segregation across the thickness of the Sb-doped ZnO epitaxial film. However, the epitaxial quality of the films deteriorated as the level of Sb dopant increased. The electrical properties of ZnO:Sb film are closely correlated with post-annealing conditions and Sb doping concentrations.

Preparation and characterization of ATO nanoparticles by various coprecipitation

A series of Sb doped SnO2 (ATO) nanoparticles, with Sb doping levels 0–20 at.% has been prepared by two different coprecipitation routes. Effect of preparation process, Sb doping concentration and calcination temperature on the crystallinity and morphology of ATO nanoparticles were investigated and analyzed. The prepared nanoparticles were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, selective area electron diffraction, X-ray diffraction and energy dispersive X-ray spectroscopy. Results indicated that the prepared ATO nanoparticles were tetragonal, and isostructural with rutile lattice structure as known from bulk SnO2. The ATO nanoparticles prepared via process I (homogeneous coprecipitation) presented obviously weaker crystallinity, smaller average crystallite size and harder agglomeration than that prepared via process II (heterogeneous coprecipitation). The crystallinity and average crystallite size of ATO nanoparticles prepared via process II increased with increasing calcination temperatures and reducing Sb doping concentrations, respectively. The increased crystallinity, dispersibility and average crystallite size for ATO nanoparticles prepared via process II may be due to the formation of ATO crystal nuclei, leading to an improved formation dynamics of ATO nanoparticles.