Overcoming Photo Degredation in Dye Sensitized Solar Cell

Dye sensitized solar cell (DSSC) is a thin film solar cell which has prospect for solving the fast growing global energy demand. It uses basically titanium dioxide TiO2, organic dye and electrolyte. The availability of these materials and their low cost makes DSSC the cheapest solar cell in the world. Although efforts are being made to improve efficiency but the short life span remain a major challenge. Improving this short life span is what this study is responding to. A known method of preparation was examined and modified for better DSSC performance. Two new approaches were introduced to the process of DSSC fabrication: the introduction of a mordant and sealing the edges. The organic pigment used for light harvesting was Teak dye. The results of the conventional method and the modified method were obtained and compared. The results of the newly developed method show a very wide improvement in the DSSC life span, and even some improvement in the efficiency. The active period of the cell increase to 60 days while the one made with the conventional approach degraded after four hours. Through these modifications, a new procedure for producing DSSC has been developed which will solve the problem of short active period in dye sensitized solar cell

Fluorescent carbon nanoparticles from Citrus sinensis as efficient sorbents for pollutant dyes

Here, we report a simple, green and economic process for the synthesis of highly fluorescent carbon nanoparticles (CPs) through low-temperature carbonization of a fruit waste, Citrus sinensis peel. This approach allows the large-scale production of aqueous CPs dispersions without any additives and post-treatment processes. The as-prepared CPs were of small particle size, exhibited bright blue fluorescence under UV irradiation ((max)=365nm) with excellent colloidal stability in water. The chemical composition, structure and morphology of the as-prepared CPs were analyzed using various spectroscopic techniques such as X-ray diffraction, transmission electron microscopy and raman spectroscopy. The formed CPs were turbostratic in nature, with a large number of functional groups on the surface. We explored the adsorption characteristics of the formed CPs for wastewater treatment. Because of the negative surface of the CPs, as evident from the zeta value, it is possible to use them for selective adsorption of the cationic dye methylene blue from a mixture of dyes. The equilibrium adsorption isotherm revealed that the Langmuir model better describes the adsorption process than the Freundlich model. As-prepared CPs rapidly adsorbed similar to 84% of the methylene blue within 1min and can be regenerated and used repeatedly. Copyright (c) 2016 John Wiley & Sons, Ltd

Simulation of Electrical Characteristics of a Solar Panel

The fast-growing photovoltaic system market leads to the necessity of the informed choice of major energy components and optimization of operating conditions in order to improve energy efficiency. Development of mathematical models of the main components of photovoltaic systems to ensure their comprehensive study is an urgent problem of improving and practical using of the technology of electrical energy production. The paper presents a mathematical model of the solar module implemented in the popular software MATLAB/Simulink. Equivalent circuit of the solar cell with a diode parallel without derived resistance is used for modelling. The serie8s resistance of the solar module is calculated by Newton's iterative method using the data of its technical specifications. It ensures high precision of simulation. Model validity was evaluated by the well-known technical characteristics of the module Solarex MSX 60. The calculation results of the experiment showed that the obtained current-voltage and current-watt characteristics of the model are compatible with those of the manufacturer

Optical and photoluminescence modulation in monolayer molybdenum sulfide thin films via electrochemical deposition: Exploring the influence of deposition voltage and time

Monolayer Molybdenum Disulfide (MoS2) exhibits a direct bandgap characterized by strong visible photoluminescence, high on/off ratio, high optical transparency, low dissipation rate, and light absorption in a wide energy spectrum. The influence of different deposition voltages and durations on the optical and photoluminescent characteristics was investigated using Raman spectroscopy, UV–visible spectrophotometry, and photoluminescence spectroscopy. All samples were analyzed for optical properties to confirm their suitability for optoelectronics. The energy band gap and Urbach energy (band tail width) of all films were 1.87 to 2.52 eV and 0.31 to 0.49 eV, respectively. The findings reveal a correlation between enhanced absorption properties and a decrease in the bandgap of the semiconducting film layers, implying the potential utility of the deposited films as efficient solar absorbers. Furthermore, the improved transmittance observed within the visible wavelength range suggests their applicability as effective window layers in thin-film photodiodes. It was established that varying the voltage and time of deposition alone can enhance the optoelectronic performance of the material in any device