Search results

The purpose of this paper is to study the optical and electrical characteristics of a single-junction solar cell based on a green-colour dye vanadyl 2,9,16, 23-tetraphenoxy-29H, 31H-phthalocyanine (VOPcPhO). The use of soluble vanadyl phthalocyanine derivative makes it very attractive for photovoltaic applications due to its tunable properties and high solubility.

A photoactive layer of VOPcPhO has been sandwiched between indium tin oxide (ITO) and aluminium (Al) electrodes to produce a ITO/PEDOT:PSS/VOPcPhO/Al photovoltaic device. The VOPcPhO thin film is deposited by a simple spin coating technique. To obtain the optimal thickness for the solar cell device, different thicknesses of the photoactive layer, achieved by manipulating the spin rate, have been investigated.

The device exhibited photovoltaic effect with the values of Jsc, Voc and FF equal to 5.26 × 10-6 A/cm2, 0.621 V and 0.33, respectively. The electronic parameters of the cell have been obtained from the analysis of current-voltage characteristics measured in dark. The values of ideality factor and barrier height were found to be 2.69 and 0.416 eV, respectively. The optical examination showed that the material is sensitive to light in the UV region between 270 nm and 410 nm, as well as in the visible spectrum within the range of 630 nm and 750 nm.

The solar cell based on a single layer of vanadyl phthalocyanine derivative results in low efficiency, which can be enhanced by introducing a variety of donor materials to form bulk heterojunction solar cells.

The spin coating technique provides a simple, less expensive and effective approach for preparing thin films.

A novel thin-film, single-junction organic solar cell, fabricated by using VOPcPhO, has been investigated for the first time ever. The vanadyl phthalocyanine derivative together with a donor material will have potential application for improved efficiency of the solar cells.

The purpose of this paper is to demonstrate the influence of annealing treatment on the photovoltaic properties of the solar cell based on ITO/PEDOT:PSS/ZnO:P3HT/Ag.

The influence of the annealing temperature and time on the P3HT/ZnO interface morphology and the ITO/PEDOT:PSS/ZnO:P3HT/Ag solar cell performance was discussed. The morphology and the current‐voltage (J‐V) characteristics were investigated by atomic force morphology (AFM) and solar simulator with an AM 1.5 G filter under an irradiation intensity of 100 mW cm⁻². The light intensity was calibrated using a standard silicon photovoltaic solar cell.

The photovoltaic performances were found to have been greatly enhanced by an annealing treatment at 145°C for 30 min.

The paper demonstrates that the annealing treatments play a crucial role in improving the morphology and J‐V performance of the ITO/PEDOT:PSS/ZnO:P3HT/Ag solar cell.

This paper aims to develop a selective energy optimisation of the photovoltaic–thermal (PV/T) system performance. The PV cell inside the PV/T system could be periodically manipulated to produce domestic hot water without applying an external power supply.

A numerical simulation model of the proposed PV/T model was developed in MATLAB/Simulink to analyse the selective energy optimisation of the model. The extrinsic cell resistance (R_se) is adjusted to control the ratio of thermal to the electrical energy, generated from the PV cell inside the PV/T system. Therefore, the internal heat of the PV cell inside the PV/T system is periodically used as a thermal element to produce electrical power and hot water.

The optimisation of PV/T energy shows that the electrical power efficiency can increase by 11.6% when R_se was 0 Ω, and the 200 L water tank temperature increased by 22ºC when R_se was 50 Ω.

This study showed that the use of the PV cell could be extended to domestic hot water and space heating, and not only for electricity.

For decades, continuous research work is going on to maximize the power harvested from the sun; however, there is only a limited analysis on exploiting the microwatt output power from indoor lightings. Microelectronic system has power demand in the µW range, and therefore, indoor photovoltaics would be appropriate for micro-energy harvesting appliances. “Energy harvesting is defined as the transfer process by which energy source is acquired from the ambient energy, stored in energy storage element and powered to the target systems”. The theory of energy harvesting is: gathering energy from surroundings and offering technological solutions such as solar energy harvesting, wind energy collection and vibration energy harvesting. “The solar cell or photovoltaic cell (PV), is a device that converts light into electric current using the photoelectric effect”. Factors such as light source, temperature, circuit connection, light intensity, angle and height can manipulate the functions of PV cells. Among these, the most noticeable factor is the light intensity that has a major impact on the operations of solar panels.

This paper aims to design an enhanced prediction model on illuminance or irradiance by an optimized artificial neural network (ANN). The input attributes or the features considered here are temperatures, maxim, TSL, VI, short circuit current, open-circuit voltage, maximum power point (MPP) voltage, MPP current and MPP power, respectively. To enhance the performance of the prediction model, the weights of ANN are optimally tuned by a new self-improved brain storm optimization (SI-BSO) model.

The superiority of the implemented work is compared and proved over the conventional models in terms of error analysis and prediction analysis. Accordingly, the presented approach was analysed and its superiority was proved over other conventional schemes such as ANN, ANN-Levenberg–Marquardt (LM), adaptive-network-based fuzzy inference system (ANFIS) and brainstorm optimization (BSO). In addition, analysis was held with respect to error measures such as mean absolute relative error (MARE), mean square root error (MSRE), mean absolute error and mean absolute percentage error. Moreover, prediction analysis was also performed that revealed the betterment of the presented model. More particularly, the proposed ANN + SI-BSO model has attained minimal error for all measures when compared to the existing schemes. More particularly, on considering the MARE, the adopted model for data set 1 was 23.61%, 48.12%, 79.39% and 90.86% better than ANN, ANN-LM, ANFIS and BSO models, respectively. Similarly, on considering data set 2, the MSRE of the implemented model was 99.87%, 70.69%, 99.57% and 94.74% better than ANN, ANN-LM, ANFIS and BSO models, respectively. Thus, the enhancement of the presented ANN + SI-BSO scheme has been validated effectively.

This work has established an improved illuminance/irradiance prediction model using the optimization concept. Here, the attributes, namely, temperature, maxim, TSL, VI, Isc, Voc, Vmpp, Impp and Pmpp were given as input to ANN, in which the weights were chosen optimally. For the optimal selection of weights, a novel ANN + SI-BSO model was established, which was an improved version of the BSO model.

Dye-sensitised solar cells (DSSCs) have attracted a great deal of interest. Dye molecules are key materials in DSSCs that produce electrons. This study reports on synthesis of the organic dyes and investigation their performance in DSSCs.

A series of new organic dyes were prepared using double rhodanine as the fundamental electron-acceptor group and aldehydes with varying substituents as the electron-donor groups. These dyes were first purified and then characterised by analytical techniques. DSSCs were fabricated to determine the photovoltaic behaviour and conversion efficiency of each individual dye.

Results demonstrated that all the dyes form j-type aggregates on the nano TiO₂. All dyes in DSSC structure show suitable power conversion efficiency, and Dye 5 due to presence of OCH₃ and OiPr presents maximum conversion efficiency.

In the search for high-efficiency organic dyes for DSSCs, development of new materials offering optimised photochemical stabilities as well as suitable optical and electrical properties is importance.

Organic dyes as photosensitisers are interesting due to low cost, relatively facile dye synthesis and capability of easy molecular tailoring.

A series of new organic metal-free dyes were prepared as sensitisers for DSSCs for the first time.

The purpose of this paper is to implement coating system by varying the amount of nano-sized titanium dioxide, (nano-TiO₂) combined with various organic binders and to study the coating effects on the performance of solar cell in terms of temperature and efficiency.

Nano-TiO₂ coatings are developed in two types of binder networks; the combination of methyltrimethoxy silane (MTMS) and nitric acid and the combination of 3-aminopropyl triethoxysilane (APTES) and MTMS. Overall, the formulations method was cost-effective, produces good transparency, clear and managed to dry at room temperature. The coating mixtures were applied onto the glass substrate by using the dip-coating method and the coated substrate were sent for several characterizations.

This study demonstrated that TiO₂ nanoparticle coating in APTES/MTMS matrix showed a thermal-decreasing result on solar cells, where the cell temperature is reduced to 46.81°C (T₂ coating type) from 55.74°C (without coating) after 1-h exposure under 1,000 W/m² irradiance in a solar simulator. Contrary to prior works where solar cell coatings were reported to reduce the cell temperature at the expense of the cell efficiency, the results from this study reported an improved fill factor (FF) of solar cells. From the photovoltaic (PV) characteristics study, the FF for solar cells is increased by approximately 0.2, i.e. 33.3 per cent, for all coatings compared to the non-coated cell.

Findings will be able to contribute in the development of temperature-reducing and efficiency-enhancing coating for PV panels.

A simple dip-coating method provides an even distribution of TiO₂ nanoparticle coating on the glass panel, which is cost-effective and time-efficient to reduce the temperature of solar cell while maintaining its efficiency.

The ability of nano-TiO₂ coatings with a simple fabrication method and the right solution to reduce the surface temperature of solar cells while improving the FF of the cells.

The purpose of this paper is to study the effect of individual layers of cadmium telluride (CdTe) solar cell to improve the efficiency of the photovoltaic cell.

To improve the performances of CdTe thin-film solar cells, the thickness of CdTe and cadmium sulfide (CdS) have been modified separately. High-efficiency ultra-thin CdTe solar cell with ZnTe layer as back surface field (BSF) was achieved. The CdTe solar cell is under AM1.5 g illumination using a one-dimensional (1-D) model, i.e. personal computer one dimensional (PC1D).

The highest conversion efficiency of about 15.3 per cent was achieved for ultrathin CdTe solar cell with a ZnTe BSF layer. The results of simulation were compared with experimental and analytical results by other researchers.

In this paper, according to the authors’ knowledge ZnO:Al/CdS/CdTe/ZnTe is simulated by PC1D model for the first time and is compared with experimental result (ZnO:Al/CdS/CdTe). The results show a suitable performance.

Tabbing and stringing are the critical process for crystalline silicon solar module production. Because of the mismatch of the thermal expansion coefficients between silicon and metal, phenomenon of cell bowing, microcracks formation or cell breakage emerge during the soldering process. The purpose of this paper is to investigate the effect of soldering on crystalline silicon solar cells and module, and reveal soldering law so as to decrease the breakage rates and improve reliability for crystalline silicon solar module.

A microscopic model of the soldering process is developed by the study of the crystalline silicon solar cell soldering process in this work. And the defects caused by soldering were analyzed systematically.

The defects caused by soldering are analyzed systematically. The optimal soldering conditions are derived for the crystalline silicon solar module.

The quality criterion of soldering for crystalline silicon solar module is built for the first time. The optimal soldering conditions are derived for the crystalline silicon solar module. This study provides insights into solder interconnection reliability in the photovoltaic (PV) industry.

The purpose of this paper is to present results of the studies on modification of ethylene-vinyl acetate (EVA) encapsulation foil to be used as thermal interface material (TIM). It is estimated that poor thermal management in electronic devices can cause over 50 per cent of failures. As the junction temperature rises, the failure rate for electronics increases exponentially. To ensure sufficient heat transfer from its source, TIMs are used in various circuits. On the other hand, it is important to ensure high electric resistivity of the designed TIM.

The focus of the investigation was twofold: modification of EVA with both graphene oxide (GO) and silver nanopowder (nAg); and TIM applicability through lamination of photovoltaic cells with standard and modified EVA foil. The main problem of a new type of encapsulant is proper gas evacuation during the lamination process. For this reason, reference and modified samples were compared taking into account the percentage of gas bubbles in visible volume of laminated TIM. Finally, reference and modified TIM samples were compared using differential scanning calorimetry (DSC) and laser flash analysis (LFA) measurements.

The proper parameters of the lamination process for the modified EVA foil - with both GO and organometallic nAg particles - were selected. The nAg addition results in an increase in thermal conductivity of the proposed compositions with respect to unmodified EVA foil, which was confirmed by DSC and LFA measurements.

The experiments confirmed the potential application of both EVA foil as a matrix for TIM material and nAg with GO as an active agent. Proposed composition can bring additional support to a solar cell or other electronic components through effective heat removal, which increases its performance.

The purpose of this paper is to find some feasible measures to solve the problems faced in China's renewable energy development and promote the industrial development of China's renewable energy.

The paper summarises the status and studies the problems of China's renewable energy industrial development, and then puts forward some proposals for the industrial development.

The paper finds that most of China's renewable energy technology is still in the transitional period from research and development to industrial production, and that the renewable energy industrial development needs the establishment of a series of technical experiments and demonstration projects to analyze and investigate the resources, the conversion and market development experience, and then form complete sets of equipment design and manufacturing, cultivation and collection of biomass resources and technology development capabilities, and that regulations should be established to provide a solid foundation for the large‐scale development of China's renewable energy. As a result, some development measures are suggested in the paper.

The paper raises the problems faced in China's renewable energy development, and gives some feasible development measures for the industrial development of China's renewable energy.