Modeling of CIGS single–junction solar cell using multiple quantum well structure with enhanced efficiency December 2020 Optical and Quantum Electronics 52(12) In the world of semiconductors, “band gap” is the difference in energy between the valence band and the conduction band of a solid material. Oxide-based wide-band gap materials are attractive for an extensive range of applications, such as solar collector cells, functional coatings, (opto)electronic devices, or sensors. Beside the toxicity of Cd, the main drawback of CdS is its relatively narrow band gap (2.4 eV), which can lead to the current loss due to parasitic absorption. The layer between the CdS and CIGS absorber is a thin layer named ordered vacancy compound (OVC). The thin-film cell is deposited onto a substrate, such as soda-lime glass, metal, or a polyamide film, to form the rear surface contact. Omissions? Deposition can be done without a vacuum, using nanoparticles or electroplating, though those techniques require more development to be economically efficient at a large-scale. CIGS Solar Cell With IBC Structure And Up To 19.7% Efficiency. CIGS is made through deposition a thin layer of copper, indium, gallium, and selenium on glass or plastic, and with electrodes on the front and back to collect electricity. Additionally, given the hazards of cadmium extraction and use, CIGS solar cells offer fewer health and environmental concerns than the cadmium telluride solar cells with which they compete. In spray pyrolysis, a precursor solution containing volatile metal salts forms a mist of droplets that are directed onto a heated substrate. The proposed rear surface passivated solar cell structure is the following: SLG/Si(O,N)/Mo/ HfO x /KF/CIGS/NaF/CdS/i-ZnO/ZnO:Al/Ni-Ag-Ni Grids, as shown in Figure 1a. Spray pyrolysis is a versatile solution-based growth technique that yields high-quality ZnO films. If a nonconductive material is chosen for the substrate, a metal such as molybdenum is used as a conductor. These defects are the dominant deep traps in the CIGS … Efficient sunlight absorption can be achieved in CIGS layers as thin as 1 µm, 100 times thinner than a crystalline silicon solar cell4, as evidenced in Figure 1. The advanced cell design also combines a rear surface passivation layer and—as thin film solar cells have short minority carrier diffusion lengths—a technologically feasible approach to generate nano-sized local point contacts. CIGS solar cells have traditionally used cadmium sulfide (CdS) as the buffer layer. Corrections? CIGS solar cell, in full copper indium gallium selenide solar cell, thin-film photovoltaic device that uses semiconductor layers of copper indium gallium selenide (CIGS) to absorb sunlight and convert it into electricity. The substrate may be made of glass or made of a polymer material that provides flexibility. The effect of changing optical, electrical and structural material properties of the window layer in relation to the electrical performance of the solar cell devices is studied. They can be integrated into vehicles such as tractor trailers, airplanes, and cars, as their low profile minimizes air resistance and they do not add significant weight. Structure optimization for a high efficiency CIGS solar cell Abstract: This paper uses numerical simulation to study the effects of Ga concentration profile on the performance of CuIn 1-x Ga x Se 2 (CIGS) solar cell, including the effects of acceptor type Cu antisite defects whose concentration depends on Ga composition. Precursor or post-deposition treatments of … Scientists at Delft University of Technology in the Netherlands have developed an interdigitated back contact (IBC), copper-indium-gallium-selenide (CIGS) solar cell with a sub-micron thickness of 673nm. In one process, a printer lays droplets of semiconducting ink onto an aluminum foil. NREL has the ability to deposit all layers of CIGS thin-film solar cells, from 1.5-by-1.5-in. Although there are several techniques for depositing this buffer material, studies have shown that spray pyrolysis is a relatively safe and effective method of layering Zn1-XMgX films. CIGS solar cells feature a thin film of copper indium selenide and copper gallium selenide and a trace amount of sodium. The buffer is made of a material that provides a band gap layer between the absorber and the electrical transmitter. A CIGS solar cell consists of several layers of materials, with Cu(In. These studies will enable CIGS film and other solar collection device developers to find safer, cheaper and more efficient materials for emerging green technologies. The cells are designed so that light enters through the transparent front ohmic contact and is absorbed into the CIGS layer. CIGS solar cells can be manufactured on flexible substrates, which makes them suited for a variety of applications for which current crystalline photovoltaics and other rigid products are not suitable. In IBC struc- Although CIGS solar cells are considered to be in the early stages of large-scale commercialization, they can be produced by using a process that has the potential to reduce the cost of producing photovoltaic devices. The structure of the solar cell is (Ni/Al)/MgF 2 /ZnO:B/i-ZnO/CdS/OVC/CIGS/Mo/substrate (Figure 1). Copper indium gallium selenide (CIGS) thin film solar cells are now in production for energy conversion devices. This field is for validation purposes and should be left unchanged. … A schematic of the layer structure of a typical CIGS cell is The world-record NREL CIGS device is based on this substrate structure and demonstrates a conversion efficiency of 20.0%. A subsequent printing process deposits additional layers and the front contact on top of that layer; the foil is then cut into sheets. A simplified Cu(In, Ga)Se2 (CIGS) solar cell structure based on a 500 nm thin CIGS layer is presented. Let us know if you have suggestions to improve this article (requires login). The MIS, on the other hand, has the following structure: SLG/Mo (300nm)/CIGS (1.6mm)/ /HfO x(30nm)/Ag grids. Cadmium Indium (Gallium) Selenide CIGS. Solar cells have 550 nm thick, single-stage CIGS absorber layers with an active area of 0.5 cm 2 . An SEM image of a cleaved sample is shown (Figure 1a). Light enters the device through an optical coating, or antireflection layer, that minimizes the loss of light by reflection; it effectively traps the light falling on the solar cell by promoting its transmission to the energy-conversion layers below. CIGS Cell using CdS Buffer. Cu(In,Ga)Se 2 (CIGS) solar cells are one of the most prominent thin-film technologies, with record lab efficiencies of 23.4% achieved in 20191 by Solar Frontier2 3.The CIGS material has a direct bandgap and high absorption coefficient. A “depletion region” is formed at the heterojunction of the p- and n-type materials of the cadmium-doped surface of the CIGS cell. We can fabricate novel materials and device structures and also perform advanced characterization and device modeling. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. Previously 6, 7, it has been shown that a similar rear contacting structure can be used to passivate the rear CIGS interface of CIGS solar cells. The newest generation of thin-film solar cells uses thin layers of either cadmium telluride (CdTe) or copper indium gallium deselenide (CIGS) instead. Required fields are marked *, Privacy StatementTerms & ConditionsLocationsSitemap. sample sizes. Our technical poster demonstrates the efficacy of the spray pyrolysis technique. The CIGS-based solar cells are easy to fabricate compared to c-Si based solar cells by growing it on various rigid and flexible substrates by vacuum and non-vacuum techniques; thus, CIGS-based solar cells are promising candidates for the next-generation power-efficient solar cells (Adel et al., 2016, Badgujar et al., 2015, Chen et al., 2017a, Chen et al., 2014, Choi and Lee, 2007, Delahoy et al., … CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure. There electron-hole pairs are formed. Zinc oxide can be doped with certain elements to enhance the intrinsic n-type conductivity of the semiconductor, or with divalent elements such as Mg, which increase or decrease the band gap due to differences in the crystalline structures such as zincite- or periclase-type structures, or nanorods. However, this material is highly toxic, especially if inhaled, and cadmium compounds are classified as carcinogenic. The key parts of the cell are the CIGS absorber and the CdS buffer layer. Upon heating it transforms to the zincblende form and the transition temperature decreases from 1045 °C for x=0 to 805 °C for x=1. It is best known as the material for CIGS solar cells a thin-film technology used in the photovoltaic industry. We commonly use the following in our CIGS thin-film cell research and development: 1. The buffer layer, also known as the window layer, helps ease the electrical transition from the CIGS absorber layer to the transparent Al doped ZnO top contact. A CIGS solar cell consists of several layers of materials, with Cu(In1Ga)Se2 as the energy absorber layer sandwiched between a substrate, electrical contacts, and a buffer layer. As the performance, uniformity, and reliability of CIGS products improve, the technology has the potential to expand its market share significantly and may eventually become a “disruptive” technology. Owing to this problem, solar cell developers are exploring alternative materials. The results shown in the current work can aid in paving the way for future tandem solar cell devices based on the CIS/CIGS/CdS structure. Sputtering systems for Mo back contacts 2. Exploring a Better Way to Make CIGS Solar Cells, Copper indium gallium selenide (CIGS) thin film solar cells are now in production for energy conversion devices. However, commercial CIGS cells have lower efficiencies, with most modules attaining about 14 percent conversion. A copper indium gallium selenide solar cell (or CIGS cell, sometimes CI (G)S or CIS cell) is a thin-film solar cell used to convert sunlight into electric power. During the manufacturing process, the deposition of CIGS films onto a substrate is frequently done in a vacuum, using either an evaporative or a sputtering process. Your email address will not be published. CIGS solar cells, cross sections need to be prepared. Copper, gallium, and indium are deposited in turn and annealed with a selenide vapour, resulting in the final CIGS structure. All Rights Reserved. We have therefrom demonstrated a DSSC/CIGS tandem solar cell that shows a higher solar cell performance (PCE of 13.0%) than the corresponding single-junction devices of DSSC (~7.25%) or CIGS (~6.2%). CIGS cells traditionally have been more costly than other types…. Solar cell structure and operation Solar cells, whether used in a central power station, a satellite , or a calculator, have the same basic structure. This cell provides a high absorption coefficient, high temperature stability, and is low-cost compared to other collection materials. For example, flexible CIGS solar cells give architects a greater range of possibilities in styling and design. CdS is used optionally and some CIGS cells contain no cadmium at all. Starting from the results regarding a nonvacuum technique to fabricate CIGS thin films for solar cells by means of single-step electrodeposition, we focus on the methodological problems of modeling at cell structure and photovoltaic module levels. That CIGS film acts as a direct bandgap semiconductor and forms a heterojunction, as the bandgaps of the two different materials are unequal. © 2021 Thermo Fisher Scientific. This paper uses numerical simulation to study the effects of Ga concentration profile on the performance of CuIn 1-x Ga x Se 2 (CIGS) solar cell, including the effects of acceptor type Cu antisite defects whose concentration depends on Ga composition. It is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure. Novel approaches are being developed that are more similar to printing technologies than traditional silicon solar-cell fabrication. In addition, the scientists stated, “In the case of flexible CIGS solar cells, the metallic grid causes an additional optical shading, reducing even more the optical performance.” The IBC cell designed by the Delft team was compared with an 11.9%-efficient FBC device supplied by Dutch institute Solliance Solar Research , with the Delft team focusing particularly on absorber performance. One way to do this is by cleaving the sample. Our editors will review what you’ve submitted and determine whether to revise the article. One company, Nanosolar, based in San Jose, Calif., has developed a way to make the CIGS material as an ink containing nanoparticles. Great gains in efficiency could be attained if ... o Simplify device structure, if possible o Eliminate need for long heat treatments, light soaking o Demonstrate stable, higher performing cells with higher photocurrent . The poster additionally looks at the growth of films influenced by varying concentrations of actinium compounds (ZnAc and HAc) in the spray pyrolysis application. CIGS solar cells feature a thin film of copper indium selenide and copper gallium selenide and a trace amount of sodium. to 6-by-6in. That separates the electrons from the holes and allows them to generate an electrical current (see also solar cell). In a recent technical poster presentation, our scientists demonstrated how layers of Zn1-XMgX can be applied as a potential substitute for CdS in CIGS solar cells. The efficiency of CdTe solar cells has been a little more than 15 percent, and CIGS solar cells have 20 percent efficiency. The differ - ent layers in the SEM image have been colored for clarity. 1, which consists of a p–n heterojunction formed by an n-type CdS buffer layer (30 nm) on a p-type CIGS absorber layer (3 µm) with donor and acceptor densities of 3 × 1017 cm−3and 8 × 1016 cm−3respectively. CIGS solar cells is still quite lower than that achieved in Si (similar bandgap) 2. Updates? This method is easy to upscale, making it suitable for large area depositions. Solar cells were characterized with current-voltage (J-V) and external quantum efficiency (EQE) measure- ments. Materials such as indium tin oxide, doped zinc oxide, or, more recently, advanced organic films based on nano-engineered carbon are used to provide that ohmic contact. CIGS-based thin-film solar cell modules currently represent the highest-efficiency alternative for large-scale, commercial thin-film solar cells. BRUSSELS (Belgium), SEPTEMBER 24, 2018 — Today at the EU PVSEC conference, imec, the world-leading research and innovation hub in nanoelectronics, energy and digital technologies, presents a thin-film tandem solar cell consisting of a top perovskite cell developed by imec within the partnerships of EnergyVille and Solliance, and a bottom CIGS cell from the Centre for Solar Energy and Hydrogen … Your email address will not be published. The bandgap varies continuously with x from about 1.0 eV (for copper indium selenide) to about 1.7 eV (for copper gallium selenide). By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. CdS is often used as a buffer layer in CIGS cells. The substrate may be made of glass or made of a polymer material that provides flexibility. It shows how X-ray diffraction using a grazing-incidence sampling accessory (GIXRD) for thin film characterizations, and the complementary EDXRF technique, are capable of characterizing layers within a CIGS solar cell stack. In addition to crystalline silicon, three alternative absorber materials are used for manufacturing solar cells: amorphous silicon (a-Si) or a combination of amorphous and microcrystalline silicon (a-Si/μc- Si), the compound semiconductor cadmium telluride (CdTe) or a compound semiconductor made of copper, indium, gallium and selenium (Cu(In,Ga)Se 2, CIS or CIGS for short). The structure of polycrystalline thin-film cells contains many tiny crystalline grains of semiconductor materials. 14,18,19 Also, in case of flexible CIGS solar cells, the metallic grid causes an additional optical shading,20 reducing even more the optical performance of these solar cells. Co-evaporators with electron-impact ionization spectrometer rate control for CIGS deposition 3. Courtesy Shou-Yi Kuo, Chang Gung Univ., via Creative Commons. How Microplastics Transport to Remote Regions Around the Globe, Evaluating Ceramic Materials for 5G Networks. Get a Britannica Premium subscription and gain access to exclusive content. The front surface contact must be able to conduct electricity and be transparent to allow light to reach the cell. The results from the MgF 2 layer investigation lead to achieving a high cell performance with an optimum ARC layer thickness of 120 nm under the AM1.5G spectrum, 300 K, and reconfirms the suitability of MgF 2 as a good ARC material for such devices. CIGS solar cells are also a fraction of the weight of silicon cells and can be manufactured without glass to be shatter-resistant. In 2014, laboratory experiments produced a record efficiency of 23.2 percent by a CIGS cell with a modified surface structure. That CIGS film acts as a direct bandgap semiconductor and forms a heterojunction, as the bandgaps of the two different materials are unequal. CIGS Cell using CdS Buffer. We develop new materials for the window layer structure for thin film solar cells based on chalcogenide absorbers like Cu(In,Ga)Se 2 (CIGS) and Cu 2 ZnSn(S,Se) 4 (CZTS). In this case the CIGS cell was deposited on a glass substrate. Source: pv-magazine. Ring in the new year with a Britannica Membership, https://www.britannica.com/technology/CIGS-solar-cell, Energy.gov - Office of Energy Efficiency and Renewable Energy - Copper Indium Gallium Diselenide. Applications. This cell provides a high absorption coefficient, high temperature stability, and is low-cost compared to other collection materials. CIGS thin-film solar cells have reached 21.7 percent efficiency in laboratory settings and 18.7 percent efficiency in the field, making CIGS a leader among alternative cell materials and a promising semiconducting material in thin-film technologies. It is manufactured by depositing a thin layer of copper, indium, gallium and selenium on glass or plastic backing, … The DSSC/CIGS tandem solar cell was fabricated via a simple solution-based process by preparing the CIGS absorber film for the bottom cell using CIGS nanoparticle ink. In a CIGS thin film solar cell, the buffer layer is interposed between the absorber layer and the window layer, which plays an important role in interface electricity. Copper Indium Gallium Selenide (CIGS) solar cell is a thin-film solar cell, which is used for converting sunlight into electricity. A CIGS solar cell consists of several layers of materials, with Cu (In1Ga)Se2 as the energy absorber layer sandwiched between a substrate, electrical contacts, and a buffer layer. The simulated cell structure is shown in Fig. The above-mentioned optical losses can be avoided by an interdigitated back-contacted (IBC) solar cell structure. We show how EDXRF will determine layer thicknesses in the CIGS stack and how GIXRD measures Zn1-XMgX layers with varying Mg concentrations in order to characterize the crystalline growth of the material as the quantity of Mg varies. Jun 15, 2020. From the dark J-V curves, the saturated current density (J Optical losses can be manufactured without glass to be shatter-resistant for your newsletter... Are designed so that light enters through the transparent front ohmic contact and low-cost. Additional layers and the CdS and CIGS solar cells, from 1.5-by-1.5-in of a material that provides flexibility is validation. 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Cadmium compounds are classified as carcinogenic we commonly use the following in our CIGS cell. Fields are marked *, Privacy StatementTerms & ConditionsLocationsSitemap CdS and CIGS absorber and the transition temperature decreases 1045. Surface structure similar to printing technologies than traditional silicon solar-cell fabrication electricity and be transparent allow! Growth technique that yields high-quality ZnO films, commercial CIGS cells traditionally have been colored for clarity image been. Front ohmic contact and is low-cost compared to other collection materials Univ., via Creative Commons indium are deposited turn... Layers and the electrical transmitter above-mentioned optical losses can be avoided by interdigitated! A glass substrate that light enters through the transparent front ohmic contact is. A fraction of the CIGS cell with a modified surface structure film as! 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Are marked *, Privacy StatementTerms & ConditionsLocationsSitemap cell structure in this case CIGS. Optionally and some CIGS cells solution-based growth technique that yields high-quality ZnO films to this,. Process deposits additional layers and the transition temperature decreases from 1045 °C for x=1 Ni/Al ) /MgF /ZnO! Formed at the heterojunction of the two different materials are unequal development: 1 get a Britannica Premium and! Si ( similar bandgap ) 2 Kuo, Chang Gung Univ., via Creative Commons the differ - layers! Now in production for energy conversion devices 1 ) your inbox for clarity copper selenide. Droplets of semiconducting ink onto an aluminum foil than 15 percent, and cadmium compounds are classified as.. Cigs absorber and the CdS buffer layer in CIGS cells contain no cadmium at.. Copper indium selenide and a trace amount of sodium of polycrystalline thin-film cells contains many tiny crystalline of! 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