Papers by Keyword: Solar Cell

Abstract: This research study utilises Essential Macleod software to optimize beam splitter for efficient hybrid photovoltaic application. The spectral splitting was carried out by alternating multilayer coating designs having Na₃AlF₆ as low index material, Y₂O₃ as middle index material and TiO₂ as high index material. The wavelength range of optimized design was selected from 400 nm to 1000 nm with reference wavelength 510 nm at an incident angle of 45. The beam splitter model comprises 56 alternating layers based on the formula [LMHM]¹⁴. The Optimac refinement approach is used to enhance the modelled structure. Different built-in analysis techniques in the essential Macleod package are also used to analyze our design, like density, total absorptance and admittance diagram. It is concluded that the modelled beam splitter transmits about 90% light in the visible spectrum range and reflects 90% light in the infrared region, which is very useful for an application like solar cells and the thermoelectric generator.

Abstract: The deposition of copper oxide utilizing a pulsed laser deposition technique employing a reactive pulsed laser as a deposition technique is the subject of this study. The wavelength of the pulsed lase used are 1064 nm, the pulse duration is 10 ns, the laser energy of 1000 mj with different substrate temperatures (200, 3300, and 400 oC). The influence of the substrate tampering on the morphological, structural, Photolumencence, and the electrical, and attributes of the fabricated solar cell was recorded and studied using a high purity cupper target and deposited on porous silicon substrates. When compared to a crystalline silicon surface, the results of AFM show a higher possibility of better absorption and hence lower reflection. The presented results revealed the properties of the fabricated solar cell as well as a noticeable improvement in the solar cell's efficiency, whether copper deposition was used or not. The deposited films at 1064 nm were monoclinic structures with a preference for the (111) direction, according to X-ray diffraction (XRD) examination. SEM were used to study the production of nanostructures on the substrate's surface, which led to the formation of small-sized and nanostructured films.

Abstract: Dye-sensitizer is heart of dye-sensitized solar cell which is an electron donor when receiving irradiation on the surface. Dye can be classified as synthesized dye or natural dye. Natural dye can be obtained colourfully from various plants such as tomato, carrot, grapes, chili, and so on. In this work, three selected plants which are locally available were chosen for three different colours. Green colour was extracted from leaves of Tiliacora triandra (Ya-nang). Red colour was from flower of Hibiscus sabdariffa (Rosella), and purple colour was from fruits of Morus alba (Mulberry). They were dried and ground into powder and their colour was extracted using 95%-ethanol. The concentrations of solution were 5, 10, and 20 g of powder per 200 ml for solvent extraction of each colour. These three colours were tested for absorbance index indicating ability of light absorption. The absorbance index curves showed that Ya-nang in green colour gave the best absorbance index having several peaks at 458 and 675 nm wavelengths for the 20 g/200 ml solution. While Rosella in red colour showed the peak at 534 nm wavelength and Mulberry in purple colour gave peak at 666 nm wavelength. The characteristics from the absorbance index curves also revealed the type of colour pigment in the dye. It was found that Ya-nang in green dye, Rosella in red dye and Mulberry in purple dye contained “Chlorophyll”, “Anthocyanin” and “Betacyanin” pigments respectively. Moreover, the area under the curves obviously indicated that the area of the green colour from Ya-nang was higher than those of Rosella and Mulberry. This implied that Ya-nang had higher potential to be dye-sensitizer and would give better dye sensitized solar performance compared with Rosella and Mulberry.

Abstract: In this work, nanostructure porous silicon surface was prepared using electrochemical etching under different current densities. I have studied the surface morphology and photoluminsense of four samples prepared at current densities 5 , 10 , 15 and 20 mA/cm²at fixed etching time 10 min.photoluminsense study showed that the energy gap of the porous silicon samples are is 3.1eV,and it was higher than the energy gap of bulk silicon which was 1.08 eV. A scanning electron microscope (SEM) micrographs were used to estimate the surface area. The surface area of the porous layer is strongly dependent on the porous layer geometry and its depth. The optical reflectance measurements were obtained by using an optical reflectometer (UV) which is equipped with an integrating sphere in the (200-1100) nm wavelength range, which reveals that the textured cells with PS layer sources have lower reflectivity value compared to the textured cell without PS structure.

Abstract: This work aims to prepare BiOI films via simple heating of BiI₃ materials and study their characters from structural, optical, and morphology perspectives. In the heating process, we varied the heating treatment time. In addition, the solar cell performance of prepared BiOI films was tested. In BiOI preparation, we deposited BiI₃ films first onto FTO substrates via BiI₃ heating in the air using a closed chamber at the temperature of 360 °C for 30, 45, and 120 minutes. The deposited BiI₃ films were then rinsed with water/ethanol and re-heated at 350 °C for 30 minutes. As a result, by increasing the heating treatment time, it could form thicker BiOI films. All the resulting films confirmed the BiOI characters. A longer BiI₃ heating time could direct the growth of BiOI crystal, wavelength red-shift, and flake structure. In the electrochemical solar cell study, it was known that BiOI films had a lower performance compared to the reported results. After a certain thickness (~1.3 μm), the device's open-circuit voltage and current decreased.

Abstract: The synthesis and characterization of spin-coated Al-doped ZnO (AZO) thin films with varying Al concentrations (0%, 5%, 10%, 15% and 20%) onto glass substrates have been demonstrated in this paper. The structural, electrical and optical properties of the spin-coated thin films have been investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) analysis, Van Der Pauw method and UV-visible spectroscopy. The EDX study shows well-defined peaks which confirm the presence of only Zn, O and Al and no other impurities in the films. The increase of Al and decrease of Zn weight percentages with increasing doping level confirms the effective substitution of Zn by Al. SEM of the surfaces of the films shows that undoped ZnO films contain particle agglomeration which is reduced with Al doping and the surfaces of the films gradually became more uniform. The thickness of the AZO films varied from 86 to 699 nm with increasing Al doping concentration. The electrical conductivity of the films increased up to ~ 7 × 10^-2 (Ω.cm)^-1 due to doping with 5% Al concentration. The optical transmittance highly increased above 95% in the visible range with the introduction of Al dopant and it kept rising with the increase of Al concentration. The optical energy band gap of undoped ZnO increased from 3.275eV to 3.342 eV with 5% Al doping.

Abstract: The long-term viability of human civilization is heavily reliant on a sustainable energy supply, and fossil fuels have long been the most sustainable source of energy. However, since fossil fuels are a non - renewable energy source, their depletion is unavoidable and inevitable in this century. Renewable energy, notably solar energy (SE), has gotten a lot of attention as a solution to this problem because it transforms SE through technology into electrical power (EP) with no environmental impact. For its inherent low unit cost and simplicity of production, organic-solar cells (OSCs) have recently been the topic of investigation for both home and commercial uses. OSCs also have a weight and flexibility benefit over standard silicon-based crystalline solar cells (CSCs). Research has suggested that dye sensitized solar cells (DSSCs) are the most effective and simple to implement of all the OSCs. In this mini review, we survey the existing DSSCs literature and attempts made to improve its performance based on mangifera indica natural dye, an eco-friendly, cost-effective, easy to extract, source of natural dye with high conversion efficiency.

Abstract: In photovoltaic system the major challenge is the cost reduction of the solar cell module to compete with those of conventional energy sources. Evolution of solar photovoltaic comprises of several generations through the last sixty years. The first generation solar cells were based on single crystal silicon and bulk polycrystalline Si wafers. The single crystal silicon solar cell has high material cost and the fabrication also requires very high energy. The second generation solar cells were based on thin film fabrication technology. Due to low temperature manufacturing process and less material requirement, remarkable cost reduction was achieved in these solar cells. Among all the thin film technologies amorphous silicon thin film solar cell is in most advanced stage of development and is commercially available. However, an inherent problem of light induced degradation in amorphous silicon hinders the higher efficiency in this kind of cell. The third generation silicon solar cells are based on nano-crystalline and nano-porous materials. Hydrogenated nanocrystalline silicon (nc-Si:H) is becoming a promising material as an absorber layer of solar cell due to its high stability with high V_oc. It is also suggested that the cause of high stability and less degradation of certain nc-Si:H films may be due to the improvement of medium range order (MRO) of the films. During the last ten years, organic, polymer, dye sensitized and perovskites materials are also attract much attention of the photovoltaic researchers as the low budget next generation PV material worldwide. Although most important challenge for those organic solar cells in practical applications is the stability issue. In this work nc-Si:H films are successfully deposited at a high deposition rate using a high pressure and a high power by Radio Frequency Plasma Enhanced Chemical Vapor Deposition (RF PECVD) technique. The transmission electron microscopy (TEM) studies show the formations of distinct nano-sized grains in the amorphous tissue with sharp crystalline orientations. Light induced degradation of photoconductivity of nc-Si:H materials have been studied. Single junction solar cells and solar module were successfully fabricated using nanocrystalline silicon as absorber layer. The optimum cell is 7.1 % efficient initially. Improvement in efficiency can be achieved by optimizing the doped layer/interface and using Ag back contact.

Abstract: There is the need for the use of biodegradable optical filters. This concept of this work is to solve the problems of electronic waste and enhance spectra filtering in photovoltaic (PV) module. The extract of the Ixora plant was used for this experiment. The extract was doped with 0.05 m of copper. The voltage peak analysis (VPA) was used to analyze the chemical stability of the filter. It was observed that the filter was chemically stable at certain time of the day due to temperature variations on the PV module.

Abstract: Electron transport layer (ETL) plays an important role in improving the performance and stability of perovskite solar cells (PSCs). SnO₂ is a good semiconductor material with high electromigration and wide band gap. TiO₂ has the advantages of superior position of conducting band (CB), long electronic life and low preparation cost, so SnO₂ and TiO₂ are often used in ETL of PSCs. In this paper, the preparation progress of SnO₂, TiO₂ and SnO₂/TiO₂ composite ETL is reviewed.