WO3-TiO2 Nanocomposite and its Applications: A Review

2018 ◽  
Vol 20 ◽  
pp. 1-26 ◽  
Author(s):  
Chin Wei Lai
Keyword(s):  
Thin Film ◽  
Band Gap ◽  
High Efficiency ◽  
Spectral Response ◽  
Visible Region ◽  
Charge Carriers ◽  
Nanocomposite Thin Film ◽  
Excitation Light ◽  
High Efficient ◽  
Potential Applications

Design and development of nanostructure of titanium dioxide (TiO2) assemblies has gained significant scientific interest and become the most studied material as it exhibits promising functional properties. Nevertheless, formation of TiO2 nanocomposite thin film, especially WO3-loaded TiO2 nanotubes without bundling is essential for high efficiency in many potential applications, including photocatalytic oxidation related applications, solar cell related applications, electrochromic devices and sensing related applications. Thus, this chapter aims to summarize on the development of an efficient WO3-loaded TiO2 nanotubes catalyst for the improving the performance for charge carriers transportation and extended the spectral response of TiO2 to visible spectrum. In fact, coupling TiO2 with W6+ species will lead to an additional electronic state in the band-gap of nanocomposite thin film, which in turn affect a change in the electronic and functionality of TiO2 itself. As a result, band gap narrowing effects could expand the range of excitation light to the visible region and provide sites that slow down the recombination of charge carriers. To bring more TiO2 related applications to the point of commercial readiness and viability in terms of performance and cost, substantial research on the development of high efficient nanocomposite thin film (WO3-TiO2) is necessary. In this chapter, different synthesis strategies and research findings for WO3-TiO2 nanocomposite thin film as well as its prospects in potential applications will be reviewed in detail.

Improved Electrical Properties of Ga2O3:Sn/CIGS Hetero-Junction Photoconductor

2014 ◽  
Vol 1635 ◽  
pp. 83-88
Author(s):  
Kenji Kikuchi ◽  
Shigeyuki Imura ◽  
Kazunori Miyakawa ◽  
Hiroshi Ohtake ◽  
Misao Kubota ◽  
...  
Keyword(s):  
Thin Film ◽  
Quantum Efficiency ◽  
Repetition Rate ◽  
Dark Current ◽  
Carrier Density ◽  
High Efficiency ◽  
Visible Region ◽  
Laser Frequency ◽  
Image Sensors ◽  
High Quantum Efficiency

ABSTRACTWe examined the potential application of CuIn1-xGaxSe1-ySy (CIGS) film for visible light image sensors. CIGS chalcopyrite semiconductors, which are representative of high efficiency thin film solar cells, have both a high absorption coefficient and high quantum efficiency. However, their dark current is too high for image sensors. In this study, we applied gallium oxide (Ga2O3) as a hole-blocking layer for CIGS thin film to reduce the dark current. The dark current of this hetero-junction was 10-9 A/cm2 at less than 7 V. Moreover, an avalanche multiplication phenomenon was observed at an applied voltage of over 8 V. However, this structure had sensitivity only in the ultraviolet light region due to the much lower carrier density of the Ga2O3 layer. We therefore used a tin-doped Ga2O3 (Ga2O3:Sn) layer deposited by pulsed laser deposition (PLD) for the n-type layer to increase the carrier density. The sensitivity of the visible region was observed in the Ga2O3:Sn/CIGS hetero-junction. We also investigated the influence of the laser frequency of the PLD on the transmittance of Ga2O3:Sn and the quantum efficiency of this hetero-junction. Ga2O3:Sn film deposited at a 0.1-Hz laser repetition rate had higher transmittance than at a 10-Hz repetition rate. The Ga2O3:Sn/CIGS hetero-junction also had a higher quantum efficiency with the lower rate (50%) than with the higher rate (30%).

A Study of Back Electrode Stacked With Low Cost Reflective Layers For High-Efficiency Thin-Film Silicon Solar Cell

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Tsung-Wei Chang ◽  
Chao-Te Liu ◽  
Wen-Hsi Lee ◽  
Yu-Jen Hsiao
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
High Performance ◽  
Silicon Solar Cell ◽  
High Efficiency ◽  
Low Cost ◽  
Visible Region ◽  
Particle Diameter ◽  
Solid Content ◽  
Thin Film Silicon

In this study, commercially available white paint is used as a pigmented dielectric reflector (PDR) in the fabrication of a low-cost back electrode stack with an Al-doped ZnO (AZO) layer for thin-film silicon solar cell applications. An initial AZO film was deposited by the radio-frequency magnetron sputtering method. In order to obtain the highest transmittance and lowest resistivity of AZO film, process parameters such as sputtering power and substrate temperature were investigated. The optimal 100-nm-thick AZO film with low resistivity and high transmittance in the visible region are 6.4 × 10−3 Ω·cm and above 80%, respectively. Using glue-like white paint doped withTiO2 nanoparticles as the PDR enhances the external quantum efficiency (EQE) of a microcrystalline silicon absorptive layer owing to the doped white particles improving Fabry–Pérot interference (FPI), which raises reflectance and scattering ability. To realize the cost down requirement, decreasing the noble metal film thickness such as a 30-nm-thick silver reflector film, and a small doping particle diameter (D50 = 135 nm) and a high solid content (20%) lead to FPI improvement and a great EQE, which is attributed to improved scattering and reflectivity because of optimum diameter (Dopt) and thicker PDR film. The results indicate that white paint can be used as a reflector coating in low-cost back-electrode structures in high-performance electronics.

Progress in Tandem PV Power Modules

1987 ◽  
Vol 95 ◽  
Author(s):  
Charles F. Gay ◽  
K. W. Mitchell
Keyword(s):  
Thin Film ◽  
Band Gap ◽  
High Efficiency ◽  
Low Cost ◽  
Selling Price ◽  
Power Modules ◽  
Copper Indium ◽  
Materials Research ◽  
Push Forward ◽  
Processing Techniques

AbstractAdvances in materials research continue to push forward the performance of thin film photovoltaic technology and bring closer to reality the goal of low cost (less than $2/wattpeak selling price), high efficiency (greater than 15%) modules. A tandem module of thin film silicon:hydrogen alloy (TFS) above copper indium diselenide (CIS) promises to be a most effective approach to this goal. The performance of the high band gap TFS and low band gap CIS has been advanced in part by understanding the nature of the materials and by optimizing the processing techniques. Careful evaluation of various alternatives has led to the selection of suitable materials to serve as the transparent conductive electrodes and the transparent optical coupler between the TFS and CIS. This paper addresses the next steps in capturing efficiency improvements and characterizes probable real world performance.

Simulation of Graded Band-Gap PIN nc-Si Thin-Film Solar Cells

2013 ◽  
Vol 345 ◽  
pp. 197-200
Author(s):  
Ming Kun Xu
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Band Gap ◽  
Fill Factor ◽  
High Efficiency ◽  
Program Package ◽  
Thin Film Solar Cells ◽  
Graded Band Gap ◽  
Si Thin Film

Using AMPS-1D program package, graded band-gap PIN nc-Si Thin-film Solar Cells is simulated. The results show that the graded band gap of intrinsic layer not only enhances the absorption of sunlight but also promote the collection of the photo-generated carriers. The increasing graded band gap PIN nc-Si thin-film solar cells with high efficiency of 14.743% and fill factor of 0.775 is superior to general solar cells designed in our previous work.

scholarly journals Spray Pyrolysed Nanostructured Gold-Doped Tin Oxide (Auto) Thin Films

2021 ◽  
Vol 25 (4) ◽  
pp. 567-572
Author(s):  
S.I. Akinsola ◽  
K.S. Adedayo ◽  
A.B. Alabi ◽  
D.B. Olanrewaju ◽  
A.A. Ajayi ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Band Gap ◽  
Spray Pyrolysis ◽  
Tin Oxide ◽  
Visible Region ◽  
Oxide Thin Film ◽  
Sno2 Thin Film ◽  
Chemical Spray Pyrolysis ◽  
Electromagnetic Spectrum

Nanostructured SnO2 thin films were grown by the chemical spray pyrolysis (CSP) method. Homemade spray pyrolysis technique is employed to prepare thin films. SnO2 is wide band gap semiconductor material whose film is deposited on glass substrate. A gold nanoparticle-doped tin oxide thin film (AuTO) was also prepared. UV-VIS (ultraviolet visible) spectroscopy and four-point probe analysis are done for optical and electrical analysis. UV-Visible absorption spectra show that the band gap of SnO2 thin film is 3.78 eV and 3.82 eV for AuTO. Band gap of SnO2 thin film can be tuned that it can be used in optical devices. The films have transmittance increases (to about 60%) and the absorbance decreases in the visible region of the electromagnetic spectrum. The electrical conductivity of the Tin Oxide is enhanced by functionalizing with the Gold nanoparticles. It is higher than that of the Tin oxide only; 0.77 x 10-2 (Ohm cm)-1 and 3.55 x 10-2 (Ohm cm)-1 for SnO2 and AuTO respectively. These properties reveal that Tin Oxide doped with gold can actually be a good material for a transparent conducting oxide to be used in photovoltaic fabrication and in electronics.

SYNTHESIS AND CHARACTERIZATION OF (ZNO)–(CO3O4) NANOCOMPOSITE VIA SPRAY PYROLYSIS PROCESS: THE USE OF THE BRUGGEMAN MODEL ON OPTICAL PROPERTIES PREVISION

2021 ◽  
pp. 2150066
Author(s):  
K. M. E. BOUREGUIG ◽  
H. TABET-DERRAZ ◽  
T. SEDDIK ◽  
M. A. BENALI
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Optical Properties ◽  
Band Gap ◽  
Spray Pyrolysis ◽  
Effective Dielectric Constant ◽  
Nanocomposite Thin Film ◽  
Bruggeman Model ◽  
Optical Dielectric Constant ◽  
Optical Dielectric

In the present paper, (ZnO)–(Co3O4) nanocomposite thin films have been prepared by using spray pyrolysis deposition on a glass substrate at 350∘C. After that, the as-obtained films have been characterized and analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and the double beam UV-visible (UV-vis) spectrophotometer. Furthermore, the Bruggeman model is used to predict the evolution of the optical dielectric constant (real and imaginary parts: [Formula: see text] and [Formula: see text] to compare them with those obtained from the experimental results. The XRD pattern reveals that the nanocomposite film has diffraction peaks 2[Formula: see text], 36.95∘ corresponding respectively to the (220), (311) planes of cubic Co3O4 and another about of 2[Formula: see text] corresponding to the (101) plane of Wurtzite ZnO. Using the Debye Scherrer formula, the crystallite size of (ZnO)[Formula: see text]–(Co3O[Formula: see text] nanocomposite is found about 32[Formula: see text]nm, while the obtained thickness of this nanocomposite is about 780[Formula: see text]nm using the DekTak Stylus profilometer. Besides, the morphology analysis shows that the nanocomposite sample is well covered without holes and/or cracks and it has uniform dense grains. The evaluation of the transmittance, reflectance, refraction index, extinction coefficient, real and imaginary parts of dielectric constant as function of wavelength illustrates that the optical response of nanocomposite thin film (ZnO)[Formula: see text]–(Co3O[Formula: see text] depends on the influence of two mediums of pure materials ZnO and Co3O4 and their interaction. In addition, the direct band gap vs incident photon energy obtained from the Tauc plot equation shows that this nanocomposite has three values of band gap energy which are [Formula: see text][Formula: see text]eV, [Formula: see text][Formula: see text]eV (correspond to pure Co3O4 film) and [Formula: see text][Formula: see text]eV (correspond to pure ZnO film). Besides, the application of the Bruggeman equation indicates that the influence of the values of volume concentration and optical dielectric constant of the ingredient nanomaterials (ZnO and Co3O[Formula: see text] is significant on the value of the effective dielectric constant of nanocomposite thin film. The specific result of this study is the similarity between the spectra obtained from the Bruggeman model and the measured one, which proves that the application of this model is useful for the prediction of the optical properties of the composite.

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