Copper Indium Gallium Selenide Tandem Solar Cells

Bifacial enhancement layers for thin film solar cells to improve their bifacial efficiency. The layers are placed over the absorber layer of the solar cell and closer to the back interface compared to the front interface. The layers absorb light with wavelengths below a cutoff frequency of the layer's absorption edge. They then emit light with longer wavelengths peaking above the cutoff. This emitted light is captured by the absorber layer when it reflects off the back surface. By selectively absorbing and reemitting light, the layers enhance the overall light absorption of the cell from both sides.

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A solar cell with enhanced recombination control through an interface layer between the absorber and p-type layers. The interface layer, comprising an electron reflector (ERF) material, prevents electron-hole recombination near the rear contact interface, while maintaining optimal absorption and conversion efficiency. The ERF layer is engineered to have a specific composition and thickness that optimizes its performance in the specific solar cell architecture. This approach enables improved solar cell efficiency compared to conventional CdTe solar cells, particularly in polycrystalline solar cells where conventional doping approaches are not feasible.

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Photovoltaic element with enhanced protection against environmental degradation through a novel rear-side barrier system. The element features a rear-side barrier that separates the photovoltaic cells from the external environment while maintaining electrical contact. The barrier is applied to the rear electrode and connected to the busbars, with a conductive interface between the rear barrier and the cells. This configuration provides dual-layer protection: the barrier layer prevents moisture and oxygen penetration, while the busbars ensure electrical integrity. The barrier's electrically insulated separation between the rear and front electrodes enables remote contact while maintaining electrical continuity.

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Flexible solar cell with improved photovoltaic performance through enhanced Cu(In,Ga)Se2 light absorption layer quality. The cell employs a flexible substrate with a double-layered rear electrode structure, where the doping layer is formed through sputtering and the rear electrode is deposited using molybdenum. The doping process introduces Na into the CIGS layer, which degrades the Ga grading and enhances photovoltaic performance characteristics such as open-circuit voltage, short-circuit current, and near-infrared absorption. The flexible substrate maintains its structural integrity while accommodating the doping process, enabling high-quality solar cells on flexible substrates.

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A solar cell manufacturing apparatus for uniform selenium deposition over large substrates. The apparatus comprises a chamber with a shower module containing a chalcogen source, where the chalcogen source is applied in a gaseous state to the substrate seated in the chamber. The shower module includes multiple shower heads with through-holes that allow the chalcogen source to pass through while maintaining a controlled flow. The shower heads are positioned on the chamber's floor to facilitate uniform deposition. The apparatus also includes a first heater to maintain the shower module temperature.

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Solar cell design featuring staggered back contacts (SBC) that eliminates the conventional shadowing effect typically present in top contact CIGS solar cells. The staggered back contacts allow photons to pass through the solar cell while maintaining structural integrity, resulting in improved power output compared to conventional top contact designs.

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Electrolytes for high-temperature solar cells that enhance output density and durability through the use of copper complexes with diverse organic ligands. The electrolyte contains multiple copper complexes with different organic ligands, which are arranged in a specific configuration to optimize performance in high-temperature environments. This configuration enables the electrolyte to maintain its electrical conductivity while protecting the solar cells from thermal degradation.

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Solar cells with improved conversion efficiency through a novel copper-infused selenium absorber layer. The absorber layer comprises a gradient of alkali metal-doped copper layers, with the first layer having a concentration of 100-9000 ppm of the first alkali metal (Li or Na) and the second layer having a concentration of 10-90 ppm of the second alkali metal (K, Rb, or Cs). This gradient layer structure enables the creation of a V-shaped band structure in the absorber layer, which enhances the photovoltaic performance compared to conventional uniform absorber layers. The gradient layer structure is achieved through a gradient of alkali metal concentrations in the lower and upper surfaces of the absorber layer, with the first layer extending to the barrier layer surface and the second layer extending to the back electrode surface.

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Copper-based chalcogenide photovoltaic cells with improved efficiency through optimized light-absorbing layer and back electrode structures. The cells feature a copper-based chalcogenide light-absorbing material with a metal electrode, where a heat-treated back electrode layer enhances the absorption layer's performance while minimizing defects. The heat-treated back electrode layer incorporates a metal intermediate layer that prevents molybdenum sulfide and selenide formation during the deposition process, thereby maintaining the absorption layer's quality. This approach enables higher efficiency than conventional copper-zinc-tin-sulfur solar cells while maintaining the benefits of the chalcogenide material.

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Thin film solar cell with enhanced photoelectric conversion efficiency through controlled surface chemistry. The cell comprises a light-absorbing layer with an alkaline element layer, followed by a second alkaline element layer, and a transparent conductive layer. The alkaline element layer in the second layer undergoes ion exchange with the light-absorbing layer, forming a new film containing alkali metal elements. This modification alters the surface chemistry of the light-absorbing layer, enhancing carrier transport and reducing surface recombination. The transparent conductive layer provides electrical contact between the layers. The modified light-absorbing layer enables improved absorption of visible light, resulting in increased photoelectric conversion efficiency.

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A copper-incorporated selenium solar cell absorber layer that enhances conversion efficiency through optimized layer composition. The absorber layer comprises a copper-rich selenium layer with a surface composition that is intermediate between pure selenium and copper-rich selenium, and a buffer layer that provides a buffer zone between the absorber layer and the p-n junction. This layered structure enables the formation of a buried pn junction, which improves the solar cell's overall efficiency compared to conventional absorber layers.

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Electrolyte for high-efficiency solar cells that combines a copper complex with a heterocyclic compound to enhance open-circuit voltage and conversion efficiency. The electrolyte contains a copper complex with multiple valences, a heterocyclic compound with multiple nitrogen rings, and a monocyclic heterocyclic compound with multiple nitrogen atoms. This combination provides a deeper valence band position for the copper complex compared to conventional inorganic p-type semiconductors, while the heterocyclic compounds enhance the electrolyte's redox properties.

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Electrolytes for high-performance solar cells that enhance density and durability through a novel heterocyclic-copper complex. The electrolyte combines a copper complex with an organic ligand and copper with multiple valences, along with an alkali metal salt, to create a unique interfacial layer that improves light absorption efficiency and maintains structural integrity under continuous operation and high-temperature conditions.

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Copper indium gallium selenide (CIGS) solar cell absorber layer for high-efficiency solar cells, comprising a prefabricated absorption layer. The absorber layer comprises indium gallium selenide (IGS) material that has been fabricated through a process of depositing and patterning the material onto a substrate. The IGS layer provides the necessary absorption properties for the solar cell, while the prefabricated structure enables efficient manufacturing of the solar cell.

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A solar cell with enhanced efficiency through a novel metallization approach that preserves the tunnel layer integrity. The cell incorporates a tunnel layer between the substrate and metallization paste, where the metallization paste forms a conductive path through the tunnel layer. This configuration enables efficient electrical connections while maintaining the tunnel layer's integrity, eliminating the need for conventional paste metallization methods that can damage the tunnel layer. The metallization paste composition is optimized to minimize purity degradation, allowing the metallization to form a reliable connection through the tunnel layer.

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Solar cell with improved light collection efficiency through optimized electrode design. The solar cell features a photoelectric conversion unit and a metal electrode with an intentionally inclined side surface. This design enables the electrode to collect light that would otherwise be reflected back into the solar cell, thereby increasing the overall light utilization rate. The inclined side surface of the metal electrode is strategically positioned to maximize light collection while maintaining structural integrity.

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Solar cells with ultra-short minority carrier lifetimes in their p-type absorber layer, achieved through controlled selenium to metal ratio in sublayers. The solar cells achieve high efficiency (15.7% average active area) with minority carrier lifetimes below 2 nanoseconds, enabling open-circuit voltages above 550 mV and achieving higher efficiency compared to conventional solar cells. The p-type absorber layer comprises a graded composition of copper indium gallium selenide sublayers with optimized selenium to metal ratios, which enables precise control over minority carrier lifetime and carrier concentration.

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A double-sided CIGS solar cell that achieves enhanced efficiency by incorporating a transparent graphene layer between the front and rear electrodes. The cell features a glass substrate, a rear electrode with patterned Mo, and a CIGS thin film. The graphene layer, which is formed on the glass substrate, enables light absorption from both the front and rear sides of the cell. The Mo patterned on the graphene layer serves as the rear electrode, allowing external light to be transmitted through the organic substrate and graphene layer. This design enables the cell to achieve higher solar efficiency compared to conventional bifacial solar cells.

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A method for preventing delamination of copper indium gallium selenide (CIGS) solar cells during the selenization process. The method involves incorporating an adhesive layer between the CIGS layer and the molybdenum back contact. This adhesive layer prevents crystallization of the CIGS layer at the Mo contact, thereby eliminating the risk of delamination during subsequent processing steps. The adhesive layer also enhances charge collection by promoting efficient electron transport through the CIGS layer.

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Screen-printable metallization pastes for forming thin oxide tunneling layers on the back-side surface of solar cells. The pastes contain metallic glass-coated particles that form conductive electrodes through screen printing, enabling efficient interdigitated back-side contact while maintaining tunnel junction integrity. The pastes can be formulated with organic binders and exhibit viscoelastic properties for high-precision screen printing.

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