Kinds Of Solar Cells Research Articles

(Invited) Sustainable Recycling of Metals from Solar Cells

The share of solar energy is increasing worldwide, leading to a widespread use of solar panels. Knowing that the 80 Mt of waste solar panels will be produced by 2050, sustainable processes must be designed in order to deal with the inevitable increase of waste solar cells in the coming years.The main advantage associated with recycling is to avoid the inevitable dispersion of hazardous materials in the environment occurring when the solar cells are landfilled. It also reduces the need for primary mineral resources and may reduce the supply risk for important components like silicon wafers, for which the production is concentrated in a few countries. The recycling process applied plays a major role to allow reducing the carbon footprint of solar cells, advocating in favour of sustainable practices for solar cells recycling.Mono-crystalline solar cells representing 90% of the market, it is therefore this kind of solar cells that are more likely to reach their end-of-life soon. Mono-crystalline solar cells are made of an aluminium frame surrounding the solar module. Underneath a glass layer, layers of ethylene vinyl acetate (EVA) encapsulate the solar cell. The solar cell in itself is made of a silicon wafer with aluminium and silver electrode as well as a silicon nitride anti-reflective coating. Recycling of the metals, particularly silver, is the main economic driver for solar cells recycling.Recycling mono-crystalline solar cells involves a mechanical removal of the aluminium frame and the junction box prior to removal of the glass and EVA layers. Different process were evaluated to get rid of EVA. Solvent-assisted dissolution allowed EVA dissolution but it requires the use of harmful solvents and often leads to breakage of the solar cell. Pyrolysis allows to recover the wafer intact while removing the glass and polymers layers. Provided that the thermal treatment is applied under an inert atmosphere, EVA decomposition leads to relatively non-toxic chemicals such as acetic acid. Recent developments include laser assisted would lead to efficient and straightforward removal of EVA.The removal of metals from the solar cells involves the use of harsh chemicals such as hydrofluoric acid for the removal of silicon nitride, nitric acid to solubilise silver and sodium hydroxide for the dissolution of aluminium. Recently, the use of aqueous brines was introduced to recover silver and aluminium from solar cells. A green and re-usable oxidising agent such as iron(III) chloride can be used to oxidise and dissolve silver, as evidenced in Figure 1, which shows a solar cells before (up) and after (down) etching, revealing the removal of the white silver lines.Using water as a solvent, silver dissolution is impossible due to the low chloride content. By increasing the chloride content, oxidation of silver and its dissolution becomes possible due to the formation of iron-chloride and silver-chloride complexes which have a different redox behaviour and a higher solubility. Overall, silver is completely dissolved in about 10 minutes without using any acids or harmful chemical. Silver can be easily recovered by precipitation or cementation, while the oxidising agent can be regenerated using oxygen from air or via electrolytic means. The objective of this presentation is to give an overview of the current recycling options and provide some guidance on the best and more sustainable practices for the complete recycling of solar cells. The choice is guided by techno-economic analysis and life cycle assessment as well as experimental demonstration of the recycling on real waste solar cells. Figure 1

Revolutionizing Energy Harvesting: Solar Cell Integration with Radio Waves for AI, IT, and Business Applications

The dynamic convergence of solar cell technologies, radio waves, information technology (IT), artificial intelligence (AI), and business applications is examined in this study. The combination of these technological components has created a diverse array of innovative opportunities that provide cost-effective, environmentally friendly, and game-changing solutions for a range of businesses. We start by exploring the basic ideas behind solar cells, demonstrating their ability to transform light from the sun into electrical energy, and looking at the various kinds of solar cells and how they work together to gather energy. With uses ranging from off-grid, rural locations to space exploration and residential and commercial installations, solar cells have emerged as key players in the shift to clean, renewable energy sources. Next, we delve into the world of radio waves, which are essential to radar systems, wireless communication, remote sensing, and other fields. We clarify the various uses of radio waves and the difficulties they pose, paving the way for their cooperation with solar cell technology. The combination of radio waves with solar cells opens up new opportunities for business, IT, and artificial intelligence applications. With this connection, off-grid communication networks may be made more sustainable and wireless devices and sensors can be installed in remote or energy-constrained areas. There could be a huge impact on AI-driven applications such as Internet of Things (IoT), smart cities, precision agriculture, and remote data collection. Integration of solar-powered radio wave technology improves sustainability, resilience, and connectedness in the field of information technology. It enables companies to improve supply chain operations, lower energy costs, operate profitably in isolated or disaster-prone places, and support sustainable practices. Among the noteworthy trends influencing the IT sector are edge computing and digital inclusion. We also examine the significant effects of solar-powered radio wave technologies on the business sector. It increases supply chain optimization, energy efficiency, environmental monitoring, and remote monitoring and control. Key themes in this environment include resilience, scalability, and sustainability. Businesses are looking for creative ways to adapt to changing customer demands and legal obligations.

Current Progress of Efficient Active Layers for Organic, Chalcogenide and Perovskite-Based Solar Cells: A Perspective

Photovoltaics has become one of the emerging alternatives to progressively supply/replace conventional energy sources, considering the potential exploitation of solar energy. Depending on the nature of the light harvester to influence on its light-absorption capability and the facility to produce electricity, different generations of solar devices have been fabricated. Early studies of organic molecules (dye sensitizers) with good absorption coefficients, going through metal chalcogenides and, lastly, the timely emergence of halide perovskites, have promoted the development of novel and low-cost solar cells with promising photoconversion efficiency (PCE), close to the well-established Si-based devices. However, main drawbacks such as the degradation/photocorrosion of the active layer, the existence of intrinsic defect sites, and the inherent toxicity of the material due to the presence of some harmful elements have blocked the future commercialization of the above kind of solar cells. In this review, we highlight the current progress in achieving efficient photomaterials for organic, chalcogenides and halide perovskites-based solar cells with the purpose of achieving high PCE values, some of which are breakthroughs in this research topic, and the diverse approaches used to extend the stability of the active layer and improve the performance of the solar devices.

Comparison and Analysis of the third generation of the solar cells

Since the current energy crisis, the efficiency of using solar cell energy has become increasingly important. In order to get a high efficiency, new kinds of solar cells would be needed, which called the third generation of solar cells. This paper review three kinds of solar cells, including the perovskite solar cells, the quantum dots solar cells and the organic solar cells. Firstly, the structure of perovskite solar cells is composed of a FTO conducting glass, a TiO2 blocking layer, a TiO2 mesoporous layer, a perovskite layer, a HTM (Hole Transport Material) layer, and mental electrode. Then, I sum up the manufacture and the development of the perovskite solar cells. Secondly, this paper analysis the structure, manufacture, and development of quantum dots solar cells. The structure of quantum dots solar cells includes the transparent conducting oxide, wide bandgap oxide semiconductor film, quantum dot sensitizer, electrolyte, and counter electrode. The third one is the organic solar cells. The structure of the organic solar cells includes layer, cathode, anode, and transparent substrate. Finally, this paper reviews the merits and defects of each solar cells.

Comparison of development prospects between silicon solar cells and perovskite solar cells

The development history, preparation process, structure and working principle of silicon solar cells and perovskite solar cells are introduced. The main parameters and production processes of the two kinds of solar cells are compared. The advantages and disadvantages of perovskite solar energy compared with existing solar cells in market application are analyzed and summarized, including good light absorption, high energy conversion efficiency and simple process flow, The problems of cost, size and stability of perovskite solar cells in market application are pointed out and the solutions are given. Perovskite solar cells have an excellent development prospect. Short circuit voltage, open circuit current and efficiency exceed those of silicon solar cells and are expected to gradually replace silicon solar cells in the market.

Development status of inverted perovskite solar cells

While the population has exploded, the world's energy demand has also risen exponentially. Energy pollution is also very severe. Therefore, it is urgent to increase the utilization of renewable new energy. Solar power has the greatest potential in the new energy sources. One kind of solar cell is the inverted perovskite solar cell (I-PSC). It has the advantages of simple device structure, high absorption coefficient, small hysteresis effect, and good defect tolerance. In this paper, the effects of electron transfer, hole transportation and manufacturing technology on the appearance of inverted perovskite-type solar cells are discussed, also the foreground of their commercialization is presented. It is believed these processes are a small step for ameliorating the photoelectric conversion efficiency and stability of these devices.

High-power microwaves response characteristics of silicon and GaAs solar cells

The high-power microwave (HPM) effect heats solar cells, which is an important component of a satellite. This creates a serious reliability problem and affects the normal operation of a satellite. In this paper, the different HPM response characteristics of two kinds of solar cells are comparatively researched by simulation. The results show that there are similarities and differences in hot spot distribution and damage mechanisms between both kinds of solar cell, which are related to the amplitude of HPM. In addition, the duty cycle of repetition frequency contributes more to the temperature accumulation of the solar cells than the carrier frequency. These results will help future research of damage assessment technology, reliability enhancement and the selection of materials for solar cells.

Life cycle assessment of organic solar cells and perovskite solar cells with graphene transparent electrodes

Indium Tin Oxide as the transparent electrode in solar cells has shown a bottleneck due to the use of scarce mental. The graphene transparent electrode (GTE) opens a sustainable route for third-generation solar cells. This work investigates the environmental performance of flexible organic solar cells and perovskite solar cells with GTEs by life cycle assessment. The manufacturing process of solar cells is developed including detailed production procedures of GTEs. The comprehensive life cycle inventories (LCIs) are provided for two kinds of solar cells. According to LCIs, life cycle impact assessment is carried on to unmask various impact categories in their full life cycles. Sensitivity analyses using the Monte Carlo method are conducted to quantify the uncertainty of final environmental impacts. The results prove that perovskite solar cells with GTEs have the shortest Energy Payback Time. A longer lifespan of both solar cells should be pursued to meet the requirement of sustainable manufacture.

Effect of tilt angle on the performance of a thin-film photovoltaic system

Solar energy is among the cleanest and most sustainable ways to enhance electrical supply's resiliency and reliability for domestic and industrial use. A Photovoltaic (PV) system is the most effective way of capturing solar energy. Long-term warranty, low-cost maintenance, and vast resource availability, solar power generation has an advantage over other approaches. Thin-film technology PV cells are a new kind of solar cell that offers an efficient technique of generating electricity from sunlight. The thin-film PV technology (FFMAT-10, Renovagen, UK) used in this study can supply 0.9 to 1.6 kW of energy to the fast-fold energy hub. The hub’s system status and configuration display battery power input, battery’s state of charge, thin-film PV power and AC power output. Two fast-fold mats (with a surface area of 25.3 m2) were connected to the energy hub. Increasing energy demand coupled with frequent power outages, and inaccessibility of electricity in rural areas necessitates the usage of PV systems at their best performance level. The study objective, therefore, sought to assess the effect of tilt angle on the performance of the thin-film PV system. The study was conducted at Kimicha in Kirinyaga County Kenya, and Juja, Kenya at tilt angles between 0o to 30o. The results indicated that the mean peak PV power for Kimicha was 347.8±231.9 W at 5o and 517.7± 131.3 W at 15ofor Juja. The maximum solar radiation during the study period was 1086.4 ±211.4 W/m2 for Juja and 973.5±219.93 W/m2 for Kimicha. From the study, it was realized that an optimal tilt angle yields optimum solar radiation that translates to maximum power production. Even though the study was conducted in two different regions, it may be applied to any other geographical location. The outcome of the study aids in acquiring self-sustaining power in the most remote locations where electricity is scarce as well as improving energy security.

The adsorption postures of water on CH3NH3PbI3 surfaces: a first-principles insight

Inorganic organic perovskite solar cells (PSCs) are a kind of solar cells with rapid development in recent years, but their poor environmental stability, such as the water degradation behavior, hinders their commercialization. Here, we have thoroughly studied the adsorption postures of water on CH3NH3PbI3 surfaces. It is found that the adsorption energy of water molecules on perovskite surfaces is [-0.63, -0.59] eV, and with different initial postures, water molecules could eventually be adsorbed above Pb atom in a horizontal structure. The interaction between the perovskite surface and water molecules mainly comes from the electron exchange of Pb-O atoms. The weak interaction between H-I atoms makes the H atom approach the I atom, which could help maintain a horizontal structure of water molecules. The interactions between perovskite surfaces and water are well explained by our DFT calculations.

Perovskite Quantum Dots in Solar Cells.

Perovskite quantum dots (PQDs) have captured a host of researchers’ attention due to their unique properties, which have been introduced to lots of optoelectronics areas, such as light‐emitting diodes, lasers, photodetectors, and solar cells. Herein, the authors aim at reviewing the achievements of PQDs applied to solar cells in recent years. The engineering concerning surface ligands, additives, and hybrid composition for PQDSCs is outlined first, followed by analyzing the reasons of undesired performance of PQDSCs. Subsequently, a novel overview that PQDs are utilized to improve the photovoltaic performance of various kinds of solar cells, is provided. Finally, this review is summarized and some challenges and perspectives concerning PQDs are also discussed.

A progress review on the modification of CZTS(e)-based thin-film solar cells

The increasing demand for energy in recent decades due to rapid industrial and population growth has resulted in a heavy dependence on non-renewable energy which leads to environmental problems. Solar energy has emerged as a promising candidate for renewable energy because its sources are unlimited and do not produce pollutants that damage the environment. Among the different kind of solar cells, CZTS(e) solar cells have the advantage of reaching the Shockley–Queisser limit (SQL) of 30.9% with low production costs, non-toxicity, and abundance of constituent elements. However, the current performance of CZTS(e) solar cells is still below the commercial performance standard of at least 20%. This review comprehensively addresses the limiting factors that prevent CZTS(e) solar cells from achieving commercial grade performance. The phenomenon behind the problem will be independently highlighted and explained how it affects performance. Then, various solving methods specific to each problem that have been carried out during the manufacturing process will be discussed. At the end of this review article, a comprehensive summary and view of the possible future prospects for the manufacture of high-efficiency CZTS(e) solar cells are provided.

Size optimization of the front electrode and solar cell using a combined finite-element-genetic algorithm method

The pattern of the front electrode and the solar cell size has a significant influence on the performance of solar cells. In order to improve the conversion efficiency of solar cells, we present a combined finite-element-genetic algorithm (GA) method for designing the front electrode and solar cell size. In the proposed method, a solar cell is considered to consist of many small unit cells, and these unit cells can well describe the current density and voltage distribution of the solar cell. In the GA, each individual represents a solar cell with a particular size and operates at a particular voltage. The validity of the proposed method is tested on the front electrode and solar cell size design problem of the side-contact and gridded cells. Two existing optimization methods are also used to optimize the front electrode and solar cell size of the two kinds of solar cells. Based on solar cells of different sizes, different optimization results are obtained using either of the two existing optimization methods. The unique optimization result can be obtained using the proposed method, and the optimization result is better than that obtained using the two existing optimization methods.

Boosting VOC of antimony chalcogenide solar cells: A review on interfaces and defects

AbstractAntimony chalcogenides, including Sb2S3, Sb2Se3, and Sb2(S,Se)3, have been developed as attractive non‐toxic and earth‐abundant solar absorber candidates among the thin‐film photovoltaic devices. Presently, a record certified power conversion efficiency of 10.5% has been demonstrated for antimony chalcogenide solar cells, which is significantly lower than that of Cu2(In,Ga)Se2 (23.35%) and CdTe (22.1%) thin‐film solar cells. The inferior performance in antimony chalcogenide solar cells is mainly owing to a large open‐circuit voltage (VOC) deficit resulted from the defect and interface‐assisted recombination. Herein, a comprehensive review on the recent advancements interface band alignment and defect passivation are carried out. This review will provide a solid understanding on the interfaces and defects of antimony chalcogenide solar cells, which is beneficial to the research and development of such kind of solar cells.

Extended quantitative characterization of solar cell from calibrated voltage-dependent electroluminescence imaging

In this paper, we derived a new method to map various optoelectronic parameters of solar cells from voltage-dependent electroluminescence imaging. To get quantitative data, we show how the voltage dependence of electroluminescence mimics a local diode current–voltage behavior, and we propose a way to measure the absolute electroluminescence flux. We therefore introduce a calibration factor generally left unknown in the literature. Example is shown on the Al-BSF silicon solar cell for which we map several parameters: diffusion lengths, dark saturation current, local voltages, and lumped series resistances with good accuracy. Comparison with other electroluminescence imaging methods is also shown. Preliminary knowledge about the sample are the spectral reflection coefficient, average dopant concentration, and back surface recombination. This method can also be derived for other kinds of solar cells by using an appropriate carrier collection model depending on their structure.

Improved design of InGaP/GaAs//Si tandem solar cells

Optimizing any tandem solar cells design before making them experimentally is an important way of reducing development costs. Hence, in this work, we have used a complete analytical model that includes the important effects in the depletion regions of the III-V compound cells in order to simulate the behavior of two and four-terminal InGaP/GaAs//Si tandem solar cells for optimizing them. The design optimization procedure is described first, and then it is shown that the expected practical efficiencies at 1 sun (AM1.5 spectrum) for both two and four-terminal tandem cells can be around 40% when the appropriate thickness for each layer is used. The optimized design for both structures includes a double MgF2/ZnS anti-reflection layer (ARC). The results show that the optimum thicknesses are 130 (MgF2) and 60 nm (ZnS), respectively, while the optimum InGaP thickness is 220 nm and GaAs optimum thickness is 1800 nm for the four-terminal tandem on a HIT silicon solar cell (with total tandem efficiency around 39.8%). These results can be compared with the recent record experimental efficiency around 35.9% for this kind of solar cells. Therefore, triple junction InGaP/GaAs//Silicon tandem solar cells continue being very attractive for further development, using high efficiency HIT silicon cell as the bottom sub-cell.

Numerical simulation of an innovative high efficiency solar cell with CdTe/Si composite absorption layer

As the improvement in efficiency of CdTe solar cell becomes more and more difficult, it is very necessary to engage in research on CdTe solar cell with innovative structure or new materials. In this work, we first proposed a design idea of constructing cadmium telluride on silicon to form a CdTe/Si composite absorption layer and then achieving an innovative high efficiency solar cell with a basic structure of n-Zn1-xMgxO/p-CdTe/p-Si/Au. This kind of solar cell has the advantages of relatively high open-circuit voltage and large short-circuit current, because photons with a wavelength range of 825 nm–1100 nm can not be absorbed by CdTe with a bandgap of 1.5 eV while they can be absorbed by silicon with a bandgap of 1.12 eV, thereby extending the long-wave response of sunlight. Numerical simulation of solar cell was carried out by using SCAPS-1D software to study the impacts of materials parameters such as thickness, doping concentration, valence band offset (VBO) and interface state density of CdTe/Si on device performances. Results indicated that thinner CdTe and suitable thick Si were beneficial for the cell with high efficiency. Particularly, the interface states between CdTe and Si severely degraded cell performance, so an innovative CdSixTey layer was proposed for the first time to effectively reduce the lattice mismatch and modify the interface properties between CdTe and Si. Finally, the highest theoretical conversion efficiency of 28.36% accompanied by open-circuit voltage of 0.838 V, short-circuit current of 39.28 mA/cm2, and fill factor of 86.11% of solar cell with SnO2:F/Zn1-xMgxO/CdTe/CdSixTey/Si/ZnTe:Mo/Au structure was obtained by optimizing numerical simulation design.

Simulation on Optimum Doping Levels in Si Solar Cells

The two key variables of an Si solar cell, i.e., emitter (n-type window layer) and base (p-type substrate) doping levels or concentrations, are studied using Medici, a 2-dimensional semiconductor device simulation tool. The substrate is ptype and 150 μm thick, the pn junction is 2 μm from the front surface, and the cell is lit on the front surface. The doping concentration ranges from 1 × 1010 cm−3 to 1 × 1020 cm−3 for both emitter and base, resulting in a matrix of 11 by 11 or a total of 121 data points. With respect to increasing donor concentration (Nd) in the emitter, the open-circuit voltage (Voc) is little affected throughout, and the short-circuit current (Isc) is affected only at a very high levels of Nd, exceeding 1 × 1019 cm−3, dropping abruptly by about 12%, i.e., from Isc = 6.05 × 10−9 A·μm−1, at Nd = 1 × 1019 cm−3 to Isc = 5.35 × 10−9 A·μm−1 at Nd = 1 × 1020 cm−3, likely due to minority-carrier, or hole, recombination at the very high doping level. With respect to increasing acceptor concentration (Na) in the base, Isc is little affected throughout, but Voc increases steadily, i.e, from Voc = 0.29 V at Na = 1 × 1012 cm−3 to 0.69 V at Na = 1 × 1018 cm−3. On average, with an order increase in Na, Voc increases by about 0.07 V, likely due to narrowing of the depletion layer and lowering of the carrier recombination at the pn junction. At the maximum output power (Pmax), a peak value of 3.25 × 10−2 W· cm−2 or 32.5 mW· cm−2 is observed at the doping combination of Nd = 1 × 1019 cm−3, a level at which Si is degenerate (being metal-like), and Na = 1 × 1017 cm−3, and minimum values of near zero are observed at very low levels of Nd ≤ 1 × 1013 cm−3. This wide variation in Pmax, even within a given kind of solar cell, indicates that selecting an optimal combination of donor and acceptor doping concentrations is likely most important in solar cell engineering.

Application of Modified MPPT Algorithms: A Comparative Study between Different Types of Solar Cells

Due to the broad needs for energy as market demands, searching on how to improve the efficiency of the PV systems is an essential concern for researchers to worry about. So, it is crucial to force the PV system to work at its peak power point in order to get the maximum available power from the photovoltaic panel. This paper presents a comprehensive comparison between four Maximum Power Point Tracking (MPPT) Algorithms; Perturb and Observe (P&O), Incremental Conductance (INC), Modified Variable Step Size Perturb and Observe (M-VSS-P&O) and Modified Variable Step Size Incremental Conductance (M-VSS-INC) by using of the DC-DC boost converter for three different kinds of solar cells. These cells are polycrystalline KC200GT cell, monocrystalline shell SQ85 cell and thin film shell ST40 cell. Simulations have been performed using MATLAB-SIMULINK for the three types of solar cells to investigate their performance under both standard test conditions (STC) and slowly varying and sudden changes in solar irradiance. The study has considered the response time, output power efficiency and steady-state-oscillations. The simulation results of the modified algorithms show an improvement in the cell performance in steady state conditions, tracking time and boost converter efficiency as well as an enhancement in the dynamic response in tracking the maximum power point (MPP) in varying climatic conditions over conventional algorithms.

Optoelectronic properties of diathiafulvalene-functionalized diketopyrrolopyrrole-fullerene molecular dyad.

Single component molecular dyad donor-acceptor junction is an important type of organic solar cells. Understanding the optoelectronic properties of molecular dyad plays the critical role to develop active layer materials for such kind of solar cells. Here, diathiafulvalene-functionalized diketopyrrolopyrrole-fullerene (DFDPP-Ful) was selected as the representative system, and the geometries, electronic structures and excitation properties of DFDPP-Ful monomer and dimer were systematically investigated based on extensive quantum chemistry calculations. The transition configurations and molecular orbitals show that the effective electron donor and acceptor are DFDPP and fullerene moieties, respectively. It also found the light harvesting is dominated by local excitation in DFDPP moiety. Meanwhile, the hybridization and quasi-degeneration between charge transfer (CT) and local excitation exist. The dimer data suggest that the increased excited states contribute to the expanding of absorption spectra, and the excitations exhibit both the intermolecular and intra-molecular CTs. Also, the remarkable CT energy differences among the different dimer models for the lowest CT excited states support the strong interface and energy disorder in such system. Therefore, the suggestions for developing molecular dyad of single component organic solar cells would be the combination of increasing light absorption, enhancing CT and local excitation hybridization, as well as suppressing energy and interface disorder by the aid of molecular design.