Quantum Well Multi-Junction Flexible Solar Cells
50 patents in this list
Updated:
Multi-junction quantum well solar cells face fundamental challenges in balancing current matching, strain management, and power conversion efficiency. Current laboratory devices achieve conversion efficiencies of 47.1% under concentrated sunlight, but maintaining these performance levels in flexible architectures requires precise control of quantum well structures where layer thicknesses range from 0.3 nm to 20 nm and barrier potentials reach 6245 kV/cm.
The engineering challenge centers on optimizing the intricate interplay between quantum well architecture, tunnel junction connectivity, and mechanical flexibility while preserving high minority carrier lifetimes and minimizing lattice defects.
This page brings together solutions from recent research—including stress-balanced multi-quantum well designs, radiative coupling mechanisms for current balancing, novel barrier layer configurations, and reverse-grown epitaxial structures. These and other approaches focus on practical implementations that maintain high beginning-of-life efficiency while enabling flexible form factors.
1. Multijunction Solar Cells with Quantum Well-Enhanced Radiative Coupling for Current Balancing
UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE AIR FORCE, 2024
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.
2. Multi-Junction Solar Cells with Stress-Balanced Multi-Quantum Well Architecture and Tunnel Junction Connectivity
YANGZHOU CHANGELIGHT CO LTD, 2024
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.
3. Multi-Junction Solar Cells with Barrier Layers for Controlled Tensile Stress and Interface Flatness
YANGZHOU CHANGELIGHT CO LTD, 2024
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.
4. Solar Cell with Strained Quantum Well Structure and Reverse-Grown Epitaxial Wafer
CETC BLUE SKY TECH CO LTD, 2023
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.
5. Quantum Well Multi-Junction Stacked Flexible Solar Cells with InGaAs/GaAsP Quantum Well Structure
SUZHOU INSTITUTE OF NANO-TECH AND NANO-BIONICS CAS, 2023
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.
6. Lattice Mismatched Multi-Junction Solar Cell with Quantum Well Structures and GaAs-Based Layer Stack
TIANJIN LANTIAN SOLAR TECH CO LTD, 2023
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.
7. Solar Cell with Quantum Well Structure and Multilayer Semiconductor Film
CHEONGJU UNIV INDUSTRY & ACADEMY COOPERATION FOUNDATION, 2023
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.
8. Infrared LED with InxGakxAs Quantum Wells and GaAs Barrier Layers for Enhanced Lattice Matching and Crystal Quality
QUANZHOU SANAN SEMICONDUCTOR TECHNOLOGY CO LTD, 2023
Invisible light-emitting diode (LED) that addresses the limitations of current infrared LEDs by achieving high efficiency and reliability through novel quantum well and barrier layer configurations. The LED comprises a semiconductor epitaxial stack with alternating quantum well and barrier layers, where the quantum well material is InxGakxAs and the barrier layer material is GaAs. This configuration enables improved lattice matching and crystal quality, particularly at wavelengths beyond 1000nm, while maintaining high luminous efficiency and reliability.
9. Solar Cell with Quantum Well Structures Integrated at pn Junction
CHEONGJU UNIVERSITY INDUSTRY & ACADEMY COOPERATION FOUNDATION, 청주대학교 산학협력단, 2023
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.
10. Multi-Junction Solar Cell with AlInGaAs/GaAsP Multi-Quantum Well Structure and Optimized Layer Composition
YANGZHOU CHANGELIGHT CO LTD, 2022
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.
11. Multi-Junction Photovoltaic Device with Alternating Bandgap Quantum Well Layers and Tunnel Junction
Shanghai Gallium Core Technology Co., Ltd., 2022
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.
12. GaAs Substrate Solar Cell with Nanopillar Structure and Intermediate Energy Band Formation
Nanjing Tech University, NANJING TECH UNIVERSITY, 2022
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.
13. Multiple Quantum Well Structure with Non-Uniform Composition Layers for Enhanced Carrier Recombination Efficiency
University of Science and Technology of China, UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA, 2021
A multiple quantum well structure for optoelectronic devices that enhances carrier recombination efficiency through non-uniform quantum well and barrier layer compositions. The structure comprises alternating layers of quantum wells and quantum barriers, where each well and barrier layer has a non-uniform composition. This non-uniformity enables enhanced carrier recombination at specific interfaces, leading to improved internal quantum efficiency, external quantum efficiency, and luminous efficiency in optoelectronic devices. The structure can be integrated into optoelectronic devices, including LEDs, lasers, and detectors, to achieve higher power output.
14. Optoelectronic Semiconductor Chip with Quantum Wells Near AlGaN Cover Layers and Specific Bandgap Properties
OSRAM OPTO SEMICONDUCTORS GMBH, 2021
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.
15. Incorporation of Strained Quantum Wells Between Base and Active Regions in Multi-Junction Solar Cells
Zhongshan Dehua Chip Technology Co., Ltd., ZHONGSHAN DEHUA CHIP TECHNOLOGY CO LTD, 2021
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.
16. Multi-Junction Solar Cell with GaInP/GaInAs/Ge Structure and Optimized Lattice Matching
SANGNI DAOTE ELECTRONIC TECHNOLOGY CO LTD, Sunny Optical Technology Co., Ltd., Nanjing Austem Electronic Information Industry Research Institute Co., Ltd., 2021
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.
17. Quantum Well Solar Cells with Gradient Bandgap and Indium Content for Enhanced Light Absorption
GALLIUM ENTERPRISES PTY LTD, Gallium Enterprises Pty Ltd, 2020
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.
18. Stacked Optoelectronic Semiconductor Device with Quantum Well Structures and Tunnel Contacts
OSRAM OPTO SEMICONDUCTORS GMBH, 2020
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.
19. Optoelectronic Semiconductor Chip with High-Barrier Layer Placement in Quantum Well Structures
OSRAM OPTO SEMICONDUCTORS GMBH, 2020
Optoelectronic semiconductor chip with enhanced radiation emission at high temperatures through the strategic placement of high-barrier layers in the active region. The chip features multiple quantum well structures with distinct barrier layers, where the high-barrier layer is positioned closer to the p-type semiconductor region. This configuration creates a charge carrier barrier effect for holes, significantly reducing recombinations outside the active region. The high-barrier layer material composition differs from the other barrier layers, enhancing its barrier properties. The chip's design enables improved radiation emission at high temperatures by mitigating the detrimental effects of charge carrier recombinations, resulting in increased brightness compared to conventional designs.
20. Multiple Quantum Well Structure with Alternating Quantum Barriers and Terminal Quantum Well Layer
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA, 2020
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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