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The purpose of this paper is to investigate a light-trapping structure based on Ag nanograting for amorphous silicon (a-Si) thin-film solar cell. Silver nanopillar arrays on indium tin oxide layer of the a-Si thin-film solar cells were designed.

The effects of the geometrical parameters such as nanopillar radius (R) and array period (P) were investigated by using the finite element simulation.

The optimization results show that the absorption of the solar cell with Ag nanopillar structure and anti-reflection film is enhanced up to 29.5 per cent under AM1.5 illumination in the 300- to 800-nm wavelength range compared with the reference cell. Furthermore, physical mechanisms of absorption enhancement at different wavelength range are discussed according to the electrical field amplitude distributions in the solar cells.

The research is still in progress. Further studies mainly focus on the performance of solar cells with different nanograting materials.

This study provides a feasible method for light-trapping structure based on Ag nanograting for a-Si thin-film solar cell.

This study is promising for the design of a-Si thin-film solar cells with enhanced performance.

The purpose of this paper is to find an optimized thin-film amorphous silicon solar cell design by numerically optimizing the light trapping efficiency of a pyramid-structured back-reflector using a frequency-domain finite element Maxwell solver. For this purpose short circuit current densities and absorption spectra within the investigated solar cell model are systematically analyzed. Furthermore, the authors employ a topology simulation method to accurately predict the material layer interfaces within the investigated solar cell model. The method simulates the chemical vapor deposition (CVD) process that is typically used to fabricate thin-film solar cells by combining a ballistic transport and reaction model (BTRM) with a level-set method in an iterative approach. Predicted solar cell models are far more realistic compared to solar cell models created assuming conformal material growth. The purpose of the topology simulation method is to increase the accuracy of thin-film solar cell models in order to facilitate highly accurate simulation results in solar cell design optimizations.

The authors perform numeric optimizations using a frequency domain finite element Maxwell solver. Topology simulations are carried out using a BTRM combined with a level-set method in an iterative fashion.

The simulation results reveal that the employed pyramid structured back-reflectors effectively increase the light path in the absorber mainly by exciting photonic waveguide modes. In using the optimization approach, the authors have identified solar cell models with cell periodicities around 480 nm and pyramid base widths around 450 nm to yield the highest short circuit current densities. Compared to equivalent solar cell models with flat back-reflectors, computed short circuit current densities are significantly increased. Furthermore, the paper finds that the solar cell models computed using the topology simulation approach represent a far more realistic approximation to a real solar cell stack compared to solar cell models computed by a conformal material growth assumption.

So far in the topology simulation approach the authors assume CVD as the material deposition process for all material layers. However, during the fabrication process sputtering (i.e. physical vapor deposition) will be employed for the Al:ZnO and ITO layers. In the framework of this ongoing research project the authors will extend the topology simulation approach to take the different material deposition processes into account. The differences in predicted material interfaces will presumably be only minor compared to the results shown here and certainly be insignificant relative to the differences the authors observe for solar cell models computed assuming conformal material growth.

The authors systematically investigate and optimize the light trapping efficiency of a pyramid nano-structured back-reflector using rigorous electromagnetic field computations with a 3D finite element Maxwell solver. To the authors’ knowledge such an investigation has not been carried out yet in the solar cell research literature. The topology simulation approach (to the best of the authors’ knowledge) has previously not been applied to the modelling of solar cells. Typically a conformal layer growth assumption is used instead.

This study aims to propose a methodology by integrating three approaches, namely, internal core technology, external knowledge flow and industrial technology development to help companies improve their decision-making quality for technology planning and enhance their research and development (R&D) portfolio efficiency.

The primary focus of this study is thin-film solar technology and patent data is retrieved from the United States Patent and Trademark Office (USPTO) database. This study presents a methodology based on the proposed integrated analysis method, constructed with patent indicators, centrality analysis of social networks and main path analysis.

The results of this study can be itemized as – the core technological competency: companies involved in two specific technology fields have lower strength in R&D portfolio than leading companies with single-core technology. Knowledge flow: most companies in a network are knowledge producers/absorbers and technological development: diverse source and sink nodes were identified in the global main path during 1997-2003, 2004-2010 and 2011-2017.

Latecomer companies can emulate leaders’ innovation and enhance their technological competence to seek niche technology. Using the global main path, companies monitor outdated technologies that can be replaced by new technologies and aid to plan R&D strategy and implement appropriate strategic decisions avoiding path dependency.

The knowledge accumulation process helps in identifying the change of position and the role of companies; understanding the trend of industrial technology knowledge helps companies to develop new technology and direct strategic decisions. The novelty of this research lies in the integrated approach of three methods aiding industries to find their internal core technical competencies and identify the external position in the competitive market.

The aim of this paper is to provide a review of the present‐day and anticipated future uses of lasers in the production of solar cells.

Following a brief introduction to photovoltaics (PV), this paper first describes the two main types of solar cell, crystalline silicon and thin film and then discusses the use of lasers in their manufacture. Finally, future developments are considered.

The paper shows that lasers are used in the manufacture of both crystalline silicon and thin film PV. Applications are many and varied, e.g. edge isolation, hole drilling, border deletion and selective doping but few are yet adopted universally across the industry. Significant future prospects exist for laser‐based processes, as solar cell manufacturers seek to improve conversion efficiency and reduce production costs.

The paper shows that lasers play a vital role in solar cell manufacture and many additional applications will arise as photovoltaic technology is further developed.

This paper presents an experimental investigation of photovoltaic (PV) properties in heterostructures consisting of indium oxide and amorphous silicon thin films, grown on a single crystalline p-type silicon and polyimide flexible substrates. Both thin films: In₂O₃ and a-Si were deposited by magnetron sputtering. Such heterostructure thin film systems are attractive because of their ability to convert solar energy into electrical one. Grown Heterostructures films were treated by simultaneous influence of an electron beam and high energetic photons with energy more than 1.5 eV in the so called vacuum photo-thermal processing (VPP).

Silicon samples of 100 Ω/sq and 45 Ω/sq were selected as substrates. Thin films deposition was done in argon atmosphere by DC magnetron sputtering.

It is shown that:

Open circuit voltage of the proposed structure may reach up to ~ 0.35 V,

Short circuit current was of no more then 10-7 A,

Polyimide materials may be used as substrates for PV thin film deposition structures,

VPP dramatically varies the photovoltaic properties of the heterostructure

Even though copper–tungsten has shown signs of potentials, relatively little is currently known about its appropriateness for photovoltaic application. This paper aims to evaluate the suitability of copper-tungs oxides as photovoltaic absorbers while investigating the consequences of oxygen content variation.

Using profilometry, Hall measurements, Seebeck test and spectrophotometry, grown samples were defined. Samples of 5 standard cubic centimeters per minute (sccm) and 7 sccm exhibited appropriate characteristics and were further tested using personal computer one dimension (PC1D) computational simulation at the system stage. To grow materials with an average thickness below 0.45 µm, magnetron co-sputtering was used. Three sample sets, varied by oxygen flow rate, were made with flow rates of 5sccm, 7sccm and 9sccm, respectively.

Some samples proved to be effective absorbers, using a cadmium telluride device as the criterion of output calculation, with one sample chosen as ideal for each type of flow rate. For the chosen samples, an optimum thickness was also obtained, i. It was discovered that thinner cells, optimal for both groups with 0.6 µm, performed better to than other thicknesses.

The material also demonstrated prospects for applications in window layers, but more needs to be known.

Thin film material properties and their operating processes are relatively complex, so it is important to find simple and cost-effective ways to forecast performance. While relatively new, numerical modeling has proven to be very useful in defining the critical properties of thin film devices, thereby helpful for predictions of performance. Solar cell capacitance simulator one dimension, amorphous semiconductor analysis, personal computer one dimension (PC1D), analysis of micro-electronic and photonic structures and automat for simulation for heterostructures (33) are several common models in the thin film industry. Due to its availability and relative ease of use, PC1D was used in this project.

As the search for the balance among performance, cost, reliability and availability continue, more absorber components continue to evolve, notably from the chalcogenides. Because of their ability to absorb light, ternary transition metal chalcogenides are useful in the production of hydrogen and in the energy storage sector, as well as in the production of light-emitting diodes and solar photovoltaic (PV).

There are several methods for the manufacture of copper–tungsten alloys, but the process of combinatorial sputtering of magnetrons provides satisfactory results even for the manufacture of various other materials. Cu₂WSe₄, an excellent alternative to sputtering, is one of the very few copper–tungsten selenide materials tested, synthesized by hot simple injection to have strong crystallinity and lacks impurity. The optical properties of colloidal Cu₂WSe₄ show that Schottky diode–like behaviors are present in the material, suggesting its potential for use in solar cells. Cu-W alloys could have a lot more to give the PV industry, by all indications. Further exploration of the oxides by this work is thus justified. Transparent conducting oxides, interfacial layers or charge-transporting compounds are commonly used as transition metal oxides. Nevertheless, as absorbers, metal oxides such as BiFeO₃ and the traditionally highly studied Cu₂O have been tested, with Cu₂O showing a conversion efficiency of up to 10% under particular conditions. This displays strong electronic and optical properties, so there might be some possibility of studying other PV absorption metal oxides. The optical properties of colloidal Cu₂WSe₄ show that Schottky diode–like behaviors are present in the material, suggesting its potential for use in solar cells.

Solar cells could make textile-based wearable systems energy independent without the need for battery replacement or recharging; however, their laundry resistance, which is prerequisite for the product acceptance of e-textiles, has been rarely examined. This paper aims to report a systematic study of the laundry durability of solar cells embedded in textiles.

This research included small commercial monocrystalline silicon solar cells which were encapsulated with functional synthetic textile materials using an industrially relevant textile lamination process and found them to reliably endure laundry washing (ISO 6330:2012). The energy harvesting capability of eight textile laminated solar cells was measured after 10–50 cycles of laundry at 40 °C and compared with light transmittance spectroscopy and visual inspection.

Five of the eight textile solar cell samples fully maintained their efficiency over the 50 laundry cycles, whereas the other three showed a 20%–27% decrease. The cells did not cause any visual damage to the fabric. The result indicates that the textile encapsulated solar cell module provides sufficient protection for the solar cells against water, washing agents and mechanical stress to endure repetitive domestic laundry.

This study used rigid monocrystalline silicon solar cells. Flexible amorphous silicon cells were excluded because of low durability in preliminary tests. Other types of solar cells were not tested.

A review of literature reveals the tendency of researchers to avoid standardized textile washing resistance testing. This study removes the most critical obstacle of textile integrated solar energy harvesting, the washing resistance.

Flexible hydrogenated amorphous silicon (a-Si:H) solar cells have many advantages, including lower weight, good flexibility and light sensitivity. Moreover, a-Si:H solar cells can be used as sensors, as indoor light sources and can also generate electricity. These solar cells are suitable for the design of portable systems and curved materials. The purpose of this study was to integrate flexible a-Si:H solar cells and wearable technology and to apply the dual functions of photovoltaics and photo sensors to smart clothing and eyewear.

The integration of flexible a-Si:H solar cells and tri-colour light-emitting diodes (LEDs) was used to develop smart auto-flashing clothing. In addition, we combined flexible a-Si:H solar cells and twisted nematic (TN) liquid crystal (LC) cells to design smart self-activation eyewear.

The maximum power resistance value of flexible a-Si:H solar cells was used to deduce the equation of solar cell voltage value generated by different percentages of SUN (100% SUN means 100 mW/cm²). A solar cell was used as a photo sensor that connects a resistor in a series to the Arduino to detect the voltage value, and then different percentages of SUN are calculated from the equation. Applying the deduced equation to the smart phone APP and Arduino code, we developed a human–machine interface (HMI) to facilitate user operation.

In this study, the flexible a-Si:H solar cell performs the function of not only photovoltaic power generation but also that of a photo sensor. The smart auto-flashing clothing is suitable for traffic guides, joggers and people engaging in other night activities. This smart self-activating eyewear can adjust to light and protect the eyes.

The purpose of this paper is to explore the use of the purchase power of the higher education system to catalyze the economy of scale necessary to ensure market competitiveness for solar photovoltaic electricity.

The approach used here was to first determine the demand necessary to construct “Solar City factories”, factories that possess equipment and processes sized, dedicated and optimized to produce only solar photovoltaic systems. Inexpensive solar cells from these factories could produce solar electricity at rates comparable to conventional fossil‐fuel derived electricity. Then it was determined if sufficient demand could be guaranteed by green purchasing from the international university system.

A focused effort from the university community to purchase on‐sight produced electricity would make it possible to construct truly large‐scale dedicated solar photovoltaic factories rather than follow the piecemeal production increases currently observed in the industry.

Direct economic competitiveness of an energy source having markedly lower environmental, social and health externalities would have a positive‐spiral (virtuous cycle) effect encouraging the transition of the global energy infrastructure away from polluting fossil fuels to green solar energy.

Despite significant commercial progress in the conversion efficiency of sunlight into electricity with solar photovoltaic cells, their widespread adoption is still limited by high costs relative to conventional fossil fuel‐based sources of electricity. The concept outlined and critically reviewed in this paper represents a novel and economical method of transitioning the electric supply system to renewable solar energy.

Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics and photovoltaics. However, the properties of ITO thin films depend on many factors. Therefore, the aim of the study was thorough investigation of the properties of sputtered ITO thin films of various thicknesses.

ITO coatings were deposited by magnetron sputtering in pure argon atmosphere using ceramic ITO target. Various deposition times resulted in obtaining thin films with different thickness, which had significant influence on the optoelectronic properties of deposited coatings. In this work the results of investigation of structural, surface, optical and electrical properties were presented.

Increase of the coating thickness caused change of the microstructure from amorphous to nanocrystalline and occurrence of grains with a size of 40 to 60 nm on their surface. Moreover, the fundamental absorption edge was red-shifted, whereas the average transmission in the visible wavelength range remained similar. Increase of the thickness caused considerable decrease of the sheet resistance and resistivity. It was found that even thin films with a thickness of 10 nm had antistatic properties.

The novelty and originality of presented work consists in, among other, determination of antistatic properties of ITO thin films with various sheet resistances that are in the range typical for dielectric and semiconducting material. To date, there are no reports on such investigations in the literature. Reported findings might be very helpful in the case of, for example, construction of transparent antireflective and antistatic multilayers.