Quantum Well Multi-Junction Flexible Solar Cells

Radiative coupling between sub-solar cells in multijunction solar cells enables current balancing through spontaneous recombination of electron-hole pairs. The technique utilizes quantum wells within the intrinsic region of the first sub-solar cell to create a radiative coupling pathway between the first and second sub-solar cells. By capturing carriers in the intrinsic region of the first sub-solar cell and sweeping them across the intrinsic region of the second sub-solar cell, excess current from the first sub-solar cell is transferred to the second sub-solar cell through radiative recombination, effectively balancing the current in the second sub-solar cell. This approach enables the creation of current-limiting sub-solar cells while maintaining high beginning-of-life efficiency.

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Multi-junction solar cells with improved efficiency through optimized bandgap engineering and structural design. The cells employ a novel multi-quantum well architecture where the middle and top sub-cells are connected through tunnel junctions, enabling enhanced spectral response and improved matching current between sub-cells. The design incorporates a stress-balanced multi-quantum well structure with undoped layers, where the quantum well is positioned in the intrinsic region. This configuration minimizes lattice defects while maintaining high minority carrier lifetimes. The cells achieve improved conversion efficiency through optimized sub-cell configurations and structural design.

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Multi-junction solar cells with improved current matching through novel barrier layer designs. The invention introduces barrier layers with specific thickness ranges (1nm to 20nm) between the InGaAs well layer and the InGaAsP barrier layer, enabling optimal tensile stress balance while minimizing dislocations. This approach enables improved current matching between the top and middle cells, enhancing overall conversion efficiency. The barrier layer design enables controlled interface flatness and atomic interdiffusion, while maintaining sufficient tensile stress for carrier transport.

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A solar cell with a strained quantum well structure that enhances load capacity through mid-bandgap broadening. The cell features a reverse-grown epitaxial wafer with a GaAs-based quantum well, comprising a GaAs base layer, a strained quantum well, and a series of tunnel junctions. The quantum well is engineered to have a barrier potential of 6245 kV/cm, with an intrinsic quantum well width of 0.3 nm, and a barrier height of 0.7 eV. The cell also includes a gradient buffer layer and an InGaAs sub-battery. The strained quantum well structure enables mid-bandgap broadening, while the tunnel junctions facilitate carrier collection and transport. The reverse growth process allows for the creation of the strained quantum well structure without requiring conventional growth conditions.

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Quantum well multi-junction stacked flexible solar cells with improved photoelectric conversion efficiency. The solar cells feature a flexible substrate, an InGaAs bottom cell, a Bragg reflector, a quantum well intermediate cell, and a GaInP top cell, with the quantum well structure comprising an undoped InGaAs/GaAsP quantum well. The solar cells achieve higher conversion efficiency through optimized barrier layer thicknesses and structural design.

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High-efficiency lattice mismatched four-junction quantum well solar cell that improves conversion efficiency beyond the theoretical limits of conventional lattice-matched triple junction cells. The cell has multiple tunnel junctions and quantum well structures. The bottom junction is GaAs. Above that is a lattice mismatched AlGaAs junction. Then comes a GaAs quantum well layer followed by a graded buffer layer. Finally, the top junction is GaAs again. This multi-layer stack allows better bandgap matching and solar spectrum absorption compared to a simple triple junction.

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Solar cell with a quantum well structure directly connected to a semiconductor pn junction structure. The cell features a quantum well insulating film and a semiconductor film with three or more alternating layers, where the quantum well insulating film is formed in a thickness range of 0.5 nm to 5 nm and the semiconductor film is formed in a width range of more than 5 nm and less than 5 nm. The cell incorporates an antireflection layer on top of the quantum well structure to prevent reflection of sunlight, and a metal layer that enables current flow through the quantum well structure. The cell achieves maximum power by optimizing the quantum well width and thickness to match the solar cell's energy gap.

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Solar cell with improved efficiency by adding quantum well structures directly connected to the pn junction of the cell. The quantum wells are sandwiched between the pn junction layers and the top and bottom electrodes. They have ultrathin insulating layers and narrow semiconductor layers alternating to form quantum wells. This allows tunneling of electrons between the wells and junction layers. It increases the bandgap and generates more electron-hole pairs from light absorption. The quantum wells can be formed on existing solar cell structures to enhance efficiency without major infrastructure changes.

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Multi-junction solar cell with a multi-quantum well structure that improves efficiency compared to conventional lattice-matched multi-junction cells. The solar cell has a sequence of sub-cells on one side of the substrate. The middle sub-cell has a multi-quantum well structure with alternating AlInGaAs and GaAsP layers. The thickness and composition of the AlInGaAs layers are different to reduce atomic diffusion and improve band alignment. This mitigates issues of lattice mismatch and interfacial diffusion in the quantum well structure.

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Dual-spectrum thin film multi-junction photovoltaic device that enables self-adaptation to various incident light spectra. The device comprises a metal electrode, multiple quantum well layers with specific bandgap energies, and a tunnel junction. The quantum well layers are arranged in a sequence with alternating bandgap energies, and the tunnel junction connects the first and second quantum well layers. The device achieves high efficiency through its unique bandgap alignment and tunneling structure, allowing it to convert light across the visible spectrum.

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Intermediate zone solar cells that achieve higher conversion efficiency through a novel design approach. The solar cell incorporates a GaAs semiconductor substrate with a specially engineered nanopillar structure that creates an intermediate energy band. This band enables the absorption of both high-energy photons and low-energy photons, significantly increasing the solar spectrum utilization. The nanopillar design, which includes a specific arrangement of quantum dots, further enhances the solar spectrum absorption while minimizing carrier recombination. This results in a solar cell with an open-circuit voltage of over 60% and a conversion efficiency that surpasses traditional solar cells.

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Optoelectronic semiconductor chip with enhanced efficiency at low current densities through optimized quantum well design. The chip features a structure where radiation-active quantum wells are positioned close to AlGaN cover layers, with a minimum separation of 0.5 nm. This proximity enables efficient charge carrier recombination in the wells, leading to increased radiation emission. The design incorporates GaN-based quantum wells with specific bandgap properties, and features multiple AlGaN layers with optimized thicknesses. The combination of these elements enables high quantum yields at low current densities while maintaining forward voltage levels.

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A method to enhance minority carrier collection in multi-junction solar cells by incorporating strained quantum wells between the base and active regions. The method introduces a strained quantum well between the base and active regions, which acts as a dislocation barrier and electron-hole recombination center. This quantum well structure is designed to match the optical band gap of the base material while maintaining lattice strain levels below 5%. The strained quantum well effectively compensates for lattice mismatch stresses and prevents dislocation propagation, thereby improving minority carrier collection efficiency and reducing recombination centers.

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Solar cell with enhanced efficiency through micro-nano architecture. The cell employs a novel multi-junction structure comprising GaInP/GaInAs/Ge photovoltaic cells with optimized lattice matching. This architecture addresses the traditional mismatched photocurrents in multi-junction solar cells by utilizing Ga0.99In0.01As as the middle layer, which has a narrower bandgap compared to Ga0.521n0.48P. The cell design enables improved efficiency through reduced internal quantum efficiency losses and enhanced overall conversion efficiency.

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Solar cells with improved light absorption and reduced stress through the use of quantum well structures with variable bandgaps. The cells incorporate multiple quantum well layers with different bandgap values, where the bandgap decreases as sunlight travels away from the surface. This design enables enhanced absorption across the solar spectrum while maintaining structural integrity. The quantum well layers are formed with varying indium content, with the highest content at the surface and decreasing as the layer moves further away from the incident solar radiation. The structure is grown on a substrate, with the quantum well layers sandwiched between barrier layers.

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Optoelectronic semiconductor device comprising stacked quantum well structures with distinct energy levels. The device comprises a first optoelectronic semiconductor component and a second optoelectronic semiconductor component stacked one above the other and electrically connected to one another via tunnel contacts. The first and second optoelectronic semiconductor components are made from semiconductor materials such as GaAs or GaP, with the first component having a multiple quantum well structure containing multiple identical unit cells arranged one above the other.

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A multiple quantum well structure for optoelectronic devices that improves quantum efficiency and reduces carrier recombination in the active region. The structure features an alternating pattern of quantum barrier layers and quantum wells, with the last quantum well layer positioned along the growth direction. This configuration enables efficient carrier confinement in the quantum wells while maintaining the barrier height across the active region, thereby enhancing light emission and reducing carrier recombination.

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Solar cell with improved interface quality between well and barrier layers in multiple quantum well structures. The cell achieves enhanced interface quality through a novel approach that addresses the interface diffusion issues typically encountered in GaInP/InGaAs/Ge lattice-matched solar cells. The solution involves a specific well-barrier layer composition that balances the diffusion rates of In and As atoms at the interface, enabling stable and efficient carrier transport across the multiple quantum well structure. This approach enables improved photovoltaic performance characteristics, including enhanced open-circuit voltage, fill factor, and overall efficiency.

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Multi-junction solar cell with a quantum well structure tunnel junction that enables efficient conversion of solar energy. The cell incorporates a quantum well tunnel junction with a bandgap of 1.7 eV, which significantly enhances the tunneling current compared to conventional materials. The manufacturing process involves creating the quantum well structure through epitaxial growth of the tunnel junction, followed by the fabrication of the multi-junction solar cell architecture.

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High-performance tunnel junctions for III-V compound semiconductor-based multijunction solar cells that achieve peak current densities exceeding 15 A/cm² under concentrated sunlight conditions. The tunnel junctions feature a p-type AlGaAs first layer with a concentration of at least 40%, followed by an n-type GaAs quantum well, and a n-type AlGaAs third layer. The design incorporates advanced semiconductor materials like InGaAsSb and InGaAsNSb, optimized quantum well thicknesses, and Se-doped layers to enhance optical transparency while maintaining high peak current densities.

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