Effect of Morphology on SnO2/MWCNT-Based DSSC Performance with Various Annealing Temperatures

2015 ◽  
Vol 1107 ◽  
pp. 649-654 ◽  
Author(s):  
Savisha Mahalingam ◽  
Huda Abdullah ◽  
Azimah Omar ◽  
Nurul Ain Md Nawi ◽  
Sahbudin Shaari ◽  
...  

Development of tin/multi-walled carbon nanotube (SnO2/MWCNTs) thin films were prepared by sol-gel method. The synthesis of tin oxide (SnO2) was carried out by dissolving tin (II) chloride (SnCl3) in a solvent of 2-methoxyethanol. Different annealing temperatures of 400 °C, 450 °C, 500 °C, 550 °C and 600 °C were proposed in this study. The changes in the structural properties were analyzed by means of transmission electron microscopy (TEM) and atomic force microscopy (AFM) analysis. AFM results indicated very rough surface area of SnO2/MWCNTs thin films where roughness values increased linearly from 1.8 nm to 11 nm by increasing the annealing temperatures from 400 °C to 600 °C. The SnO2/MWCNTs-based DSSC exhibited good photovoltaic performance with power conversion efficiency (η), photocurrent density (Jsc), open circuit voltage (Voc) and fill factor (FF) of 0.62 %, 5.6 mA cm-2, 0.55 V and 0.65 respectively. The obtained structural and photovoltaic performance analysis was proposed as a suitable benchmark for Sn/MWCNTs based dye-sensitized solar cell (DSSC) application.

2014 ◽  
Vol 911 ◽  
pp. 266-270 ◽  
Author(s):  
Huda Abdullah ◽  
Savisha Mahalingam ◽  
Azimah Omar ◽  
Mohd Zikri Razali ◽  
Sahbudin Shaari ◽  
...  

Development of platinum incorporating graphene (pt/graphene) thin films was prepared by sol-gel method via chemical bath deposition (CBD). Indium oxide (In2O3) as photoanode and pt/graphene as counter electrode is used to analyse the characteristics and performance of dye-sensitized solar cell (DSSC). Different annealing temperatures of 200 oC, 250 oC and 300 oC were proposed for the counter electrode in this study. The changes in the structural properties were analyzed by means of X-ray Diffraction (XRD) and atomic force microscopy (AFM) analysis. AFM results indicated very rough surface area of graphene sheet where roughness values decreased linearly from 0.65 μm to 0.18 μm by an increment in annealing temperature. The In2O3-based DSSC exhibited good photovoltaic performance with power conversion efficiency (η), photocurrent density (Jsc), open circuit voltage (Voc) and fill factor (FF) of 0.47 %, 5.46 mA cm-2, 0.54 V and 0.36 respectively. The obtained structural and photovoltaic performance analysis was proposed as a suitable benchmark for pt/graphene counter electrode with In2O3-based DSSC.


2001 ◽  
Vol 16 (6) ◽  
pp. 1626-1631 ◽  
Author(s):  
A. Karthikeyan ◽  
Rui M. Almeida

An investigation of phase separation phenomena in gel and glassy thin films of silica–titania, with TiO2 contents of 20 and 40 mol%, has been carried out by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The thin films were prepared by spin coating of a precursor sol on silicon wafers. Both the TEM measurements (carried out on scrapped thin film flakes) and the AFM measurements (carried out on films coated on the silicon substrates) for samples with different heat treatments suggest that spinodal-like structural inhomogeneities occur in these samples, unlike the corresponding observations in pure silica films, which are known to be homogeneous. Changes in the microstructure of the films have been noticed with the thermal treatment, in agreement with earlier x-ray photoemission studies. The finer characteristic dimensions of the phase separated regions reveal that silica–titania samples prepared by sol-gel processing exhibit a more intimate mixing of the phases.


2019 ◽  
Vol 286 ◽  
pp. 49-63
Author(s):  
Dwight Acosta ◽  
Francisco Hernández ◽  
Alejandra López-Suárez ◽  
Carlos Magaña

WO3:Mo and WO3:Ti thin films have been deposited on FTO/Glass substrates by the pulsed chemical spray technique at a substrate temperature of Ts= 450°C. The influence of Mo and Ti doping on the structural, electrical, and optical behavior of WO3thin films, has been studied by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Ultra Violet and Visible Spectrometry (UV-VIS), and Surface Conductivity Methods (Four Points). Doped WO3films presents similar polycrystalline structures but with noticeable modifications in surface configurations at micrometric and nanometric levels, as the Mo and Ti concentration is systematically increased in the starting sprayed solution. From processed High-Resolution Electron Micrographs (HREM), a low density of structural defects was found on pure and doped WO3grains. This lead to conclude that variations in films surface characteristics are mainly related with metallic doping concentrations which in turn, have noticeable influence in electrical and optical behaviors reported in this work.


1999 ◽  
Vol 597 ◽  
Author(s):  
M. Siegert ◽  
Judit G. Lisoni ◽  
C. H. Lei ◽  
A. Eckau ◽  
W. Zander ◽  
...  

AbstractIn the process of developing thin film electro-optical waveguides we investigated the influence of different substrates on the optical and structural properties of epitaxial BaTiO3 thin films. These films are grown by on-axis pulsed laser deposition (PLD) on MgO(100), MgAl2O4(100), SrTiO3(100) and MgO buffered A12O3(1102) substrates. The waveguide losses and the refractive indices were measured with a prism coupling setup. The optical data are correlated to the results of Rutherford backscattering spectrometry/ion channeling (RBS/C). X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM). BaTiO3 films on MgO(100) substrates show planar waveguide losses of 3 dB/cm and ridge waveguide losses of 5 dB/cm at a wavelength of 633 nm.


2001 ◽  
Vol 688 ◽  
Author(s):  
J. Rodríguez Contreras ◽  
J. Schubert ◽  
U. Poppe ◽  
O. Trithaveesak ◽  
K. Szot ◽  
...  

AbstractWe have prepared single crystalline epitaxial PbZr0.52Ti0.48O3 (PZT) and BaTiO3 (BTO) thin films on single crystalline epitaxial SrRuO3 (SRO) thin films grown on SrTiO3 (100) (STO) substrates. PZT and SRO thin films were grown using high-pressure on-axis sputtering and BTO using pulsed laser deposition (PLD). The film thickness ranged between 12 to 165 nm. Their excellent structural properties, surface smoothness and interface sharpness were demonstrated by X-Ray Diffraction measurements (XRD), High Resolution Transmission Electron Microscopy (HRTEM) and Atomic Force Microscopy (AFM). Rutherford Backscattering Spectrometry and Channeling measurements (RBS/C) were used to analyze stoichiometry and crystalline quality. Ferroelectric hysteresis loops were obtained for all films of a thickness down to 12 nm showing a decrease in the remanent polarization Pr and an increase in the coercive field Ec towards thinner film thicknesses. Furthermore we have prepared tunneling junctions with a PZT or BTO barrier thickness of 3-6 nm. Reproducible bi-stable I-V-curves and bias dependence of the conductance were obtained suggesting an influence of the ferroelectric properties of the barrier material on the tunnel current.


2012 ◽  
Vol 151 ◽  
pp. 314-318
Author(s):  
Ching Fang Tseng ◽  
Cheng Hsing Hsu ◽  
Chun Hung Lai

This paper describes microstructure characteristics of MgAl2O4 thin films were deposited by sol-gel method with various preheating temperatures and annealing temperatures. Particular attention will be paid to the effects of a thermal treatment in air ambient on the physical properties. The annealed films were characterized using X-ray diffraction. The surface morphologies of treatment film were examined by scanning electron microscopy and atomic force microscopy. At a preheating temperature of 300oC and an annealing temperature of 700oC, the MgAl2O4 films with 9 μm thickness possess a dielectric constant of 9 at 1 kHz and a dissipation factor of 0.18 at 1 kHz.


1996 ◽  
Vol 436 ◽  
Author(s):  
Cengiz S. Ozkan ◽  
William D. Nix ◽  
Huajian Gao

AbstractHeteroepitaxial Si1-xGex. thin films deposited on silicon substrates exhibit surface roughening via surface diffusion under the effect of a compressive stress which is caused by a lattice mismatch. In these films, surface roughening can take place in the form of ridges which can be aligned along <100> or <110> directions, depending on the film thickness. In this paper, we investigate this anisotropic dependence of surface roughening and present an analysis of it. We have studied the surface roughening behaviour of 18% Ge and 22% Ge thin films subjected to controlled annealing experiments. Transmission electron microscopy and atomic force microscopy have been used to study the morphology and microstructure of the surface ridges and the dislocations that form during annealing.


2002 ◽  
Vol 16 (28n29) ◽  
pp. 4347-4351 ◽  
Author(s):  
H. PRESTING ◽  
J. KONLE ◽  
H. KIBBEL

Silicon solar cells with embedded germanium (Ge) layers deposited as 3-dimensional islands in the Stranski-Krastanov growth mode have been grown by molecular beam epitaxy (MBE) to enhance the efficiency of Si thin film solar cells. The Ge-layers increase the infrared absorption in the base of the cell to achieve higher photocurrent which should overcome the loss in the open circuit voltage due to incorporation of a smaller bandgap material in the heterostructure. Up to 75 layers of Ge, each about 8 monolayers (ML) thick, separated by Si-spacer layers (9-18nm) have been deposited at rather elevated temperatures (700°C) on a standard 10Ωcm p-type Si-substrate. Island densities of 1011 cm -2 have been achieved by use of antimony (Sb) as surfactant. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) were used to characterize the growth of Ge-islands under variuos growth conditions. Photocurrent measurements exhibit a higher photo-response in the infrared regime but a lower open circuit voltage of the fabricated solar cells compared to a Si-reference cell.


2001 ◽  
Vol 665 ◽  
Author(s):  
Andrei Yu. Andreev ◽  
Helmut Sitter ◽  
Christoph J. Brabec ◽  
Peter Hinterdorfer ◽  
Günter Springholz ◽  
...  

ABSTRACTWe have studied the structure and growth regularities of highly ordered para-sexiphenyl (C36H26) thin films deposited by Hot Wall Epitaxy on mica. In particular, atomic force microscopy (AFM) was used to investigate the early growth stage of these films, in order to find the process controlling parameters. It was shown that the substrate temperature and the growth time are important parameters for control of the film morphology, in terms of the degree of anisotropy and long range order. X-ray diffraction pole figure technique and transmission electron microscopy were also used to characterize the crystallographic structure of the thicker films. We have shown that the highly ordered crystallites of para-sexiphenyl (showing needle-like morphology by AFM) are oriented with their (11 1 ) or (11 2 ) crystallographic planes parallel to the substrate surface. For each of these two orientations there are two opposite directions for growth of crystallites reflecting the two-fold symmetry of the mica surface.


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