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. 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. If a nonconductive material is chosen for the substrate, a metal such as molybdenum is used as a conductor. CIGS Cell using CdS Buffer. One way to do this is by cleaving the sample. However, commercial CIGS cells have lower efficiencies, with most modules attaining about 14 percent conversion. The simulated cell structure is shown in Fig. Copper Indium Gallium Selenide (CIGS) solar cell is a thin-film solar cell, which is used for converting sunlight into electricity. 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. A simplified Cu(In, Ga)Se2 (CIGS) solar cell structure based on a 500 nm thin CIGS layer is presented. The structure of the solar cell is (Ni/Al)/MgF 2 /ZnO:B/i-ZnO/CdS/OVC/CIGS/Mo/substrate (Figure 1). The efficiency of CdTe solar cells has been a little more than 15 percent, and CIGS solar cells have 20 percent efficiency. Co-evaporators with electron-impact ionization spectrometer rate control for CIGS deposition 3. The MIS, on the other hand, has the following structure: SLG/Mo (300nm)/CIGS (1.6mm)/ /HfO x(30nm)/Ag grids. 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). By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. All Rights Reserved. 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. An SEM image of a cleaved sample is shown (Figure 1a). These defects are the dominant deep traps in the CIGS … The newest generation of thin-film solar cells uses thin layers of either cadmium telluride (CdTe) or copper indium gallium deselenide (CIGS) instead. CIGS Cell using CdS Buffer. CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure. Let us know if you have suggestions to improve this article (requires login). In IBC struc- CIGS solar cells are also a fraction of the weight of silicon cells and can be manufactured without glass to be shatter-resistant. This field is for validation purposes and should be left unchanged. A “depletion region” is formed at the heterojunction of the p- and n-type materials of the cadmium-doped surface of the CIGS cell. CIGS solar cells feature a thin film of copper indium selenide and copper gallium selenide and a trace amount of sodium. 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. 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. Omissions? 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. Required fields are marked *, Privacy StatementTerms & ConditionsLocationsSitemap. CIGS cells traditionally have been more costly than other types…. In the world of semiconductors, “band gap” is the difference in energy between the valence band and the conduction band of a solid material. 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. In one process, a printer lays droplets of semiconducting ink onto an aluminum foil. 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. The world-record NREL CIGS device is based on this substrate structure and demonstrates a conversion efficiency of 20.0%. Solar cells were characterized with current-voltage (J-V) and external quantum efficiency (EQE) measure- ments. sample sizes. That separates the electrons from the holes and allows them to generate an electrical current (see also solar cell). 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. Solar cells have 550 nm thick, single-stage CIGS absorber layers with an active area of 0.5 cm 2 . The bandgap varies continuously with x from about 1.0 eV (for copper indium selenide) to about 1.7 eV (for copper gallium selenide). Source: pv-magazine. That CIGS film acts as a direct bandgap semiconductor and forms a heterojunction, as the bandgaps of the two different materials are unequal. Spray pyrolysis is a versatile solution-based growth technique that yields high-quality ZnO films. However, this material is highly toxic, especially if inhaled, and cadmium compounds are classified as carcinogenic. Owing to this problem, solar cell developers are exploring alternative materials. Your email address will not be published. Cadmium Indium (Gallium) Selenide CIGS. The poster additionally looks at the growth of films influenced by varying concentrations of actinium compounds (ZnAc and HAc) in the spray pyrolysis application. Precursor or post-deposition treatments of … The substrate may be made of glass or made of a polymer material that provides flexibility. 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 . © 2021 Thermo Fisher Scientific. 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. 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. The substrate may be made of glass or made of a polymer material that provides flexibility. 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. 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. Novel approaches are being developed that are more similar to printing technologies than traditional silicon solar-cell fabrication. Updates? Copper, gallium, and indium are deposited in turn and annealed with a selenide vapour, resulting in the final CIGS structure. 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. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. This cell provides a high absorption coefficient, high temperature stability, and is low-cost compared to other collection materials. 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. Jun 15, 2020. CIGS-based thin-film solar cell modules currently represent the highest-efficiency alternative for large-scale, commercial thin-film solar cells. NREL has the ability to deposit all layers of CIGS thin-film solar cells, from 1.5-by-1.5-in. Applications. It is best known as the material for CIGS solar cells a thin-film technology used in the photovoltaic industry. 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. This method is easy to upscale, making it suitable for large area depositions. These studies will enable CIGS film and other solar collection device developers to find safer, cheaper and more efficient materials for emerging green technologies. For example, flexible CIGS solar cells give architects a greater range of possibilities in styling and design. 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. 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. 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