Bidyut Barman

A Review on Thermophysical Properties of Nanoparticle-Enhanced Phase Change Materials for Thermal Energy Storage

A review of current experimental studies on variations in thermophysical properties of phase change material (PCM) due to dispersion of highly-conductive nanoparticles , coined as nanoparticle-enhanced PCMs (NePCMs), is presented in this article. The NePCMs may be considered as a solution to improve latent heat thermal energy storage performance. Thermophysical properties such as thermal conductivity, latent heat, viscosity and super cooling of PCMs could be changed for different physical properties of dispersed nanoparticle such as size, shape, concentration and surface properties. The present review focuses on the studies that describe the effect of addition of nanoparticles on the thermophysical properties of PCM with the help of available explanations in the literature.

Study of formation and influence of surface plasmonic silver nanoparticles in efficiency enhancement for c-Si solar cells

Plasmonic nanoparticles based thin film solar cells are playing a crucial role in designing the current breed of third generation solar cells, using light scattering and trapping properties. In present work, we demonstrated the technique for the fabrication of silver nanoparticles (NPs) showing surface plasmonic effects. The Rapid Thermal Annealing (RTA) technique has been used to create Ag NPs on as sputtered thin film on c-Si wafer. The surface morphology, plasmonic resonance peak have analyzed and it has been observed that the surface plasmonic peak and average NP size can easily be tuned within the desired wavelength range. It has been observed that the maximum reflection reduction is found to be around 2.15% for particular annealing temperature and duration indicating average size of around 60 nm.

Study of Growth of Silver Nanoparticles as Plasmonic Layer on pc-Si Wafer to Enhance the Efficiency of Solar Cells

Localized Surface Plasmon Resonance (LSPR) phenomena are of great interest in the field of thin film solar cells due to its light trapping capabilities using metallic nanoparticles . In this research work, we have investigated the surface plasmonic effect on textured poly crystalline silicon (Tpc-Si) substrate with Ag Nanoparticles. The maximum reflection reduction of ~13 % with average nanoparticles size ~35 nm for 250 °C and 20 min annealing temperature and duration respectively, has been observed in the wavelength range 300–800 nm. As a consequence reflection reduction in the solar cell which in turn increase in absorption of light especially in the higher wavelength region which can increase the efficiency of poly crystalline solar cells.

Effect of Temperature and Ferro-Fluid on Rotation of Rare Earth Magnet Used for Clean Energy Generation

Herein, we have tested kerosene and transformer oil based Ferro-fluids and optimized the rpm of the rare earth magnet (REM) for the best possible efficiency. Rotation per minute of the REM decreases with increase in temperature in case of kerosene oil based Ferro-fluids, whereas it increases with increase in temperature in case of kerosene oil based Ferro-fluids. In the tested system, REM exhibit similar rpm around 50 °C for both the Ferro-fluids. At room temperature clean energy can be generated in this circular model by using kerosene oil based Ferro-fluid. The maximum voltage and current of 0.2 V and 0.2 mA can be generated in this model with kerosene oil based Ferro-fluid at room temperature.

Theoretical Analysis of Surface Plasmonic Ag Nanoparticles Embedded in C-, Pc-, a-Si Thin-Film Solar Cell, Using Mie Scattering

Current research shows that, Light trapping mechanism using metallic Nanoparticles has shown a promising way to increase light absorption in thin film solar cells to a significant level. In this present work, we have investigated the effect of C-scattering and Q-scattering of light shown by silver nanoparticles embedded in different substrates using Mie scattering theory. We have observed, Silver nanoparticles embedded in monocrystalline silicon substrates showed better C scattering compared to all other substrates. Here we report a red shift of Surface plasmonic resonance of scattering as the particle size increases. Also the plasmonic behavior depends on the type of substrate used.

Thermal properties of nano-graphite-embedded magnesium chloride hexahydrate phase change composites

Phase change materials can provide large heat storage density with low volume. But their low thermal conductivity limits their heat transfer capabilities. Since carbonaceous nanoparticles have a good thermal conductivity they can be applied as an additive to phase change materials to increase their heat transfer rate. In this study, nano-graphite is used as an additive and the influences of its various concentrations on the thermal conductivity and melting and freezing rate for the nanoparticle-enhanced phase change materials is experimentally investigated. Experimental results indicates a reduction of 22% in melting time and a reduction of 75% in solidification time of 0.5% nano-graphite-embedded phase change material.

Solar thermal charging properties of graphene oxide embedded myristic acid composites phase change material

The present paper reports the heat transfer characteristics of graphene oxide (GO) embedded myristic acid based phase change material (GO-PCM) composites. By varying concentrations of GO (0.1-0.5 wt%), different GO-PCM composites were preapred. Two different experimental setups were used for investigating the heat transfer characteristics of the prepared GO-PCM composites during the melting and solidification processes: (i) conventional heating and (ii) solar illumination. The experimental observations indicated a higher heat transfer rate in the GO-PCM composites as compared to pristine PCM for both experimental setups. From the experimental results of conventional heating setup, it was observed that the melting and solidification rate for GO–PCM composites, at 0.5 wt% of GO, increased by 48% and 70%, respectively in comparison to pristine PCM. The experimental results using solar illumination setup demonstrated an ultrafast heating rate for GO-PCM composites than the conventional heating based approach.