Optical Modeling of Gold nanoparticles (Au NP) for efficiency improvement of a-Si:H photovoltaic cells

2014 ◽  
Vol 1671 ◽  
Author(s):  
Peiqing Yu ◽  
Jean-Philippe Blondeau ◽  
Caroline Andreazza ◽  
Esidor Ntsoenzok ◽  
Julien Roussel ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Surface Coverage ◽  
Thermal Evaporation ◽  
Active Material ◽  
Optical Path Length ◽  
Localized Surface Plasmon ◽  
Optical Modeling ◽  
Mean Size ◽  
Refractive Medium ◽  
Uv Visible

ABSTRACTThe efficiency of thin-film solar cells using a-Si:H is limited by the decrease in a-Si:H layer optical path length and its poor light absorption at red and NIR wavelengths. Metal NP such as Au have been shown to increase the absorption in the active material and then cell performances, by exhibiting localized surface plasmon (LSP) resonances. Our work’s goal is to understand NP influence in such cells, to perform an optimal structure by increasing the amount of light absorbed within the cell using NP scattering and luminescence. Modeling based on Mie theory is first carried out using bulk Palik data for Au spheres with various diameters and refractive medium indexes. Using modeling parameters, Au layers were deposited on glass and SnO2 substrates respectively by thermal evaporation in vacuum and sputtering, followed by thermal annealing (200 ∼ 500°C) in order to promote the NP growth. MEB pictures show quasispherical Au NP shape with a mean size of 150nm. This diameter range switches extinction of NP in scattering regime. Annealing temperature (T) strongly affects the NP morphology. Surface coverage decreases and sphericity appears to increase with T. UV-Visible spectroscopy displays distinct LSP resonances around 600nm after annealing with a red shift while T increases.

Tuning the Localized Surface Plasmon Resonance of Al-Al2O3 Nanosphere Towards NIR Region by Gold Coating

2020 ◽  
Vol 12 ◽  
Author(s):  
Jyoti Katyal ◽  
Shivani Gautam
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Dielectric Layer ◽  
Electric Field Distribution ◽  
Active Material ◽  
Visible Region ◽  
Field Enhancement ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Al Nanoparticles

Background: A relatively narrow LSPR peak and a strong inter band transition ranging around 800 nm makes Al strongly plasmonic active material. Usually, Al nanoparticles are preferred for UV-plasmonic as the SPR of small size Al nanoparticles locates in deep UV-UV region of the optical spectrum. This paper focused on tuning the LSPR of Al nanostructure towards infrared region by coating Au layer. The proposed structure has Au as outer layer which prevent the further oxidation of Al nanostructure. Methods: The Finite Difference Time Domain (FDTD) and Plasmon Hybridization Theory has been used to evaluated the LSPR and field enhancement of single and dimer Al-Al2O3-Au MDM nanostructure. Results: It is observed that the resonance mode show dependence on the thickness of Al2O3 layer and also on the composition of nanostructure. The Au layered MDM nanostructure shows two peak of equal intensities simultaneously in UV and visible region tuned to NIR region. The extinction spectra and electric field distribution profiles of dimer nanoparticles are compared with monomer to reveal the extent of coupling. The dimer configuration shows higher field enhancement ~107 at 1049 nm. By optimizing the thickness of dielectric layer the MDM nanostructure can be used over UV-visible-NIR region. Conclusion: The LSPR peak shows dependence on the thickness of dielectric layer and also on the composition of nanostructure. It has been observed that optimization of size and thickness of dielectric layer can provide two peaks of equal intensities in UV and Visible region which is advantageous for many applications. The electric field distribution profiles of dimer MDM nanostructure enhanced the field by ~107 in visible and NIR region shows its potential towards SERS substrate. The results of this study will provide valuable information for the optimization of LSPR of Al-Al2O3-Au MDM nanostructure to have high field enhancement.

Elaboration and Characterization of Mg-Doped ZnO Thin Films by Thermal Evaporation: Annealing Temperature Effect

2021 ◽  
Author(s):  
Fouaz Lekoui ◽  
Salim Hassani ◽  
Mohammed Ouchabane ◽  
Hocine Akkari ◽  
Driss Dergham ◽  
...  
Keyword(s):  
Thin Films ◽  
Temperature Effect ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Zno Thin Films ◽  
Doped Zno ◽  
Mg Doped

scholarly journals Characterization of Zinc oxide Nanostructures prepared by hydrothermal method with Antibacterial property

2019 ◽  
Vol 17 (42) ◽  
pp. 108-124
Author(s):  
Ibrahim Abdulkareem Ali
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Crystallite Size ◽  
Annealing Temperature ◽  
Energy Gap ◽  
Antibacterial Property ◽  
Zno Nanostructures ◽  
Zinc Oxide Nanostructures ◽  
Oxide Nanostructures ◽  
Uv Visible

        In this study, Zinc oxide nanostructures were synthesized via a hydrothermal method by using zinc nitrate hexahydrate and sodium hydroxide as a precursor. Three different annealing temperatures were used to study their effect on ZnO NSs properties. The synthesized nanostructure was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Atomic force microscope (AFM), and Fourier Transform Infrared Spectroscopy (FTIR). Their optical properties were studied by using UV -visible spectroscopy. The XRD analysis confirms that all ZnO nanostructures have the hexagonal wurtzite structure with average crystallite size within the range of (30.59 - 34.52) nm. The crystallite size increased due to the incensement of annealing temperature. FESEM analysis indicates that ZnO has hexagonal shape of cylindrical pores, plate-like nanocrystals and Nanorods. AFM analysis shows that the average surface roughness of ZnO Nanostructures increases from 3.96 to 19.1 nm with the increase of annealing temperature. The FTIR peaks indicate successful preparation of ZnO Nanostructures. The FTIR method was used to analyses the chemical bonds which conformed the present of the Zn-O group in the region between (400-500) cm-1. The UV-visible showed a red shift in the absorption spectra related to the shift in the energy gap related to increase in the particle size.  the band gap energy has been calculated from the optical absorption spectra. The annealing process has been fond more effective on the value of energy gap. As the annealing temperature increases, the value of energy gap, increases as well; from (3.12to 3.22) eV. The prepared Nanostructure is used for antibacterial property. It shows strong antibacterial activity against S. aureus and P.aeuruginosa bacteria by the agar disc diffusion method. The white precipitate of ZnO NSs has superior antibacterial activity on gram-positive (S. aureus) than the gram-negative (P.aeuruginosa) bacteria.

Structural and Optical Properties of TiO2 Thin Films Prepared by Thermal Oxidation of Ti Thin Films

2013 ◽  
Vol 770 ◽  
pp. 225-228
Author(s):  
L. Uttayan ◽  
K. Aiempanakit ◽  
M. Horprathum ◽  
P. Eiamchai ◽  
V. Pattantsetakul ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Thermal Oxidation ◽  
Annealing Temperature ◽  
Oxidation Process ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Wafer Substrate ◽  
Uv Visible ◽  
Ti Films

Titanium dioxide (TiO2) films were prepared by thermal oxidation from Ti films. The Ti films were deposited on glass and silicon (100) wafer substrate by dc magnetron sputtering and subsequent with thermal oxidation process. The crystal structure and morphology of TiO2 films were estimated by using X-ray diffractometry (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The optical property of TiO2 films was determined by UV-Visible spectrophotometer. The influences of annealing temperature between 200 to 500°C in air for 1 hour on the structure and optical properties of TiO2 films were investigated. The increasing of annealing temperature was directly affected the phase transition from Ti to TiO2. The optical and structural properties of TiO2 films are the best exhibited with increasing the annealing temperature at 500 °C.

scholarly journals Annealing Effect on the Thermoelectric Properties of Bi2Te3Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Chi-Pi Lin
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Method ◽  
Si Substrates ◽  
Seebeck Coefficients

Bismuth telluride-based compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, thermal evaporation processes were adopted to fabricate the n-type Bi2Te3thin films on SiO2/Si substrates. The influence of thermal annealing on the microstructures and thermoelectric properties of Bi2Te3thin films was investigated in temperature range 100–250°C. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor were enhanced as the annealing temperature increased. When the annealing temperature increased to 250°C for 30 min, the Seebeck coefficient and power factor of n-type Bi2Te3-based thin films were found to be about −132.02 μV/K and 6.05 μW/cm·K2, respectively.

scholarly journals Bandgap Engineering of Bilayer Ge/CdS Thin Films via Interlayer Diffusion under Different Annealing Temperatures

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Faheem Amin ◽  
Syedah Afsheen Zahra ◽  
Muhammad Sultan ◽  
Sajjad Hussain Mirza ◽  
Fahad Azad
Keyword(s):  
Thin Films ◽  
Glass Substrate ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Rutherford Backscattering ◽  
Bandgap Engineering ◽  
Thermal Evaporation Method ◽  
Annealing Temperatures ◽  
Cds Thin Films

Bilayer thin films of Ge/CdS have been deposited on a glass substrate through thermal evaporation method. The obtained Ge/CdS samples were annealed at temperatures up to 400°C to observe the resulting effect on the structural changes in the film. The bandgap of the annealed films was found to increase with increasing annealing temperature which can be attributed to the increased interlayer diffusion. The interlayer diffusion was found to take effect above a temperature of 300°C which was confirmed by the Rutherford backscattering technique. Complementary XPS was done to investigate the surface stoichiometry of the bilayers.

Size decrease of detonation nanodiamonds by air annealing investigated by AFM

MRS Advances ◽  
2016 ◽  
Vol 1 (16) ◽  
pp. 1067-1073 ◽  
Author(s):  
Stepan Stehlik ◽  
Daria Miliaieva ◽  
Marian Varga ◽  
Alexander Kromka ◽  
Bohuslav Rezek
Keyword(s):  
Size Distribution ◽  
Annealing Temperature ◽  
Detonation Nanodiamonds ◽  
Particle Analysis ◽  
Detonation Synthesis ◽  
Size Distributions ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mean Size ◽  
The Mean

ABSTRACTNanodiamonds (NDs) represent a novel nanomaterial applicable from biomedicine to spintronics. Here we study ability of air annealing to further decrease the typical 5 nm NDs produced by detonation synthesis. We use atomic force microscopy (AFM) with sub-nm resolution to directly measure individual detonation nanodiamonds (DNDs) on a flat Si substrate. By means of particle analysis we obtain their accurate and statistically relevant size distributions. Using this approach, we characterize evolution of the size distribution as a function of time and annealing temperature: i) at constant time (25 min) with changing temperature (480, 490, 500°C) and ii) at constant temperature (490°C) with changing time (10, 25, 50 min). We show that the mean size of DNDs can be controllably reduced from 4.5 nm to 1.8 nm without noticeable particle loss and down to 1.3 nm with 36% yield. By air annealing the size distribution changes from Gaussian to lognormal with a steep edge around 1 nm, indicating instability of DNDs below 1 nm.

Characteristics of Alumina Films Formed by the Annealed Aluminum Films at High Temperatures in Air

2013 ◽  
Vol 652-654 ◽  
pp. 371-374
Author(s):  
Jing Lv
Keyword(s):  
Phase Transformations ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Technique ◽  
Aluminum Films ◽  
Alumina Films ◽  
Measurement Results ◽  
Evaporation Technique ◽  
Α Al2o3 ◽  
Quartz Substrates

Al films (about 40 nm) were prepared on quartz substrates by thermal evaporation technique, and subsequently annealed in air for 1h at temperature ranging from 600 to 1300oC. The characteristics of the annealed films were investigated in this paper. The measurement results of XRD and Raman show that crystalline phase transformations of the annealed films will convert from γ, γ and α, up to α-Al2O3 with the increasing of the annealing temperature at 600 oC, 1200 oC, to 1300oC. AFM and transmission spectra reveal the effects of phase transformations on their morphology and optical properties.

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