Photonic Structures for Quantum Dot Solar Cells

Lead sulfide quantum dot solar cell structure and method that enhances photoelectric conversion efficiency through an optimized electron transport layer. The cell architecture incorporates a zinc oxide film with an engineered optical wrinkle structure as the electron transport layer, which enables efficient light utilization by the photoactive layer. This unique layer design enables improved absorption and utilization of incident light, thereby increasing short-circuit current density.

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Heterojunction PbS quantum dot solar cell with enhanced light absorption and charge collection through nanostructured PN junction layers. The cell features a stacked glass substrate with a nano-patterned PbS quantum dot layer, followed by a PN junction layer with ZnO nanoparticles as optical antennas. The ZnO nanoparticles serve as efficient light-harvesting materials while maintaining electronic inertness, enabling improved charge collection and filling factor. The nanostructured architecture enables efficient light absorption and carrier transport through the PbS quantum dot layer, while the PN junction layer enhances charge collection at the contact interface.

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Photoelectric conversion element with enhanced sensitivity and reduced dark current through selective quantum dot layer engineering. The element comprises a photoelectric conversion layer, a first electrode, and a second electrode. The first electrode collects holes generated in the photoelectric conversion layer, while the second electrode collects electrons generated in the photoelectric conversion layer. The conversion layer consists of a first quantum dot layer and a second quantum dot layer. The first quantum dot layer contains quantum dots with a surface modified with a first ligand, while the second quantum dot layer contains quantum dots with a surface modified with a second ligand that is different from the first ligand. The second quantum dot layer has an ionization potential greater than that of the first quantum dot layer. The second quantum dot layer's particle size distribution is controlled to achieve a narrower distribution compared to the first quantum dot layer.

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Quantum dot stacked solar cell with enhanced light energy utilization through a novel transparent conductive layer. The cell comprises a front cell, a transparent conductive intermediate layer, a rear cell, and a counter electrode. The transparent conductive layer is achieved by magnetron sputtering an ITO film with a thickness of 20 nm on the front cell. The rear cell is prepared by magnetron sputtering a PbS quantum dot layer with a thickness of 80 nm on the front cell. The counter electrode is a metal electrode. The transparent conductive layer significantly improves the light energy utilization rate of the solar cell by reducing transmission losses, while the PbS quantum dot layer enhances the conversion efficiency through its narrow emission spectrum.

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Silver telluride-zinc sulfide core-shell structure quantum dots for enhanced solar concentrator performance. The dots achieve high near-infrared emission while maintaining environmental safety through the use of silver telluride and zinc sulfide. The core-shell structure provides improved stability and photoluminescence quantum yield compared to conventional quantum dots. The preparation method enables the synthesis of these quantum dots through a controlled thermal treatment process that preserves their photoluminescent properties.

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A hybrid light trapping structure for quantum dot intermediate band solar cells that combines dielectric nanopyramid arrays with a reflective layer. The structure comprises a dielectric film on the upper surface of the solar cell, followed by a first dielectric nanopyramid array layer, and then a second dielectric nano-pyramid array layer on the lower surface of the solar cell. The reflective layer is positioned on the lower surface of the second dielectric nano-pyramid array layer. This configuration enhances light absorption by both increasing the light trapping effect of the dielectric nanopyramid array layer and reducing electrical losses through the reflective layer.

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Photoelectric conversion element with improved sensitivity and dynamic range through quantum dot-based light detection. The element comprises a photoelectric conversion layer comprising three or more quantum dot layers, each with surface-modifying ligands that modify the quantum dot surfaces. The quantum dot layers are arranged with specific bandgap energy relationships, where the energy of the quantum dot closer to the first electrode is smaller than the energy of the quantum dot closer to the second electrode. This arrangement enables the conversion of visible light into electrical signals across a broad spectral range, with the quantum dot energy matching the desired detection wavelength.

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Multi-intermediate band quantum dot solar cell with improved efficiency by using multiple quantum dot layers with different bandgaps to absorb a broader range of low-energy photons. The cell has a stack of quantum dot layers on an N-type semiconductor, each layer having a different bandgap. This allows absorption of sub-bandgap photons that cannot be absorbed by a single intermediate band. The layers are sandwiched between N-type and P-type semiconductors to form a solar cell.

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A light trapping structure for quantum dot solar cells like InAs/GaAsSb to improve absorption over a wide wavelength range. The structure consists of densely arranged curved nanowires growing out of pyramid-shaped frustums. The nanowires bend more at one end near the frustum top compared to the other end. This asymmetric bending provides enhanced light trapping by scattering and total internal reflection. The structure can be fabricated using plasma etching. It reduces reflectance below 1500 nm and has an average reflectance of less than 5% in the 300-1300 nm range.

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Transparent solar cells that maximize the utilization of short-wavelength light in solar cells. The cells employ a quantum dot-based photovoltaic layer that absorbs and converts short-wavelength radiation, while simultaneously emitting longer wavelengths through excited state conversion. This dual-function layer enables efficient conversion of both visible and ultraviolet light, thereby increasing overall solar cell efficiency. The transparent cathode layer is optimized for maximum absorption of the absorbed short-wavelength light, while the encapsulation layer provides reflective protection for the excited quantum dot material.

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Solar cells with quantum-structured materials and/or layers of quantum-structured materials incorporated therein achieve high open circuit voltages through novel device architectures. The cells incorporate a wide band gap material in both the emitter and depletion region adjacent to the emitter, with a wider energy gap extended emitter structure featuring material in both the emitter and depletion region. This design enables improved carrier collection while minimizing dark current, particularly in optically-thin solar cells.

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Quantum dot intermediate zone solar cell with semiconductor nanopore structure that achieves higher efficiency than traditional quantum dot solar cells by exploiting the unique optical properties of quantum dot interband transitions. The cell incorporates periodic semiconductor nanopore structures with dielectric layers that contain quantum dots and spacers, enabling the creation of a quantum dot intermediate zone. The dielectric layers are composed of quantum dots and a spacer layer, with the buffer layer forming a type II quantum dot structure. This arrangement enables the creation of an intermediate zone with enhanced absorption of photons below the semiconductor bandgap, while maintaining carrier recombination rates. The cell achieves higher efficiency than conventional quantum dot solar cells through the controlled absorption of photons in the intermediate zone.

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A shell-core nanowire solar cell architecture that improves efficiency and reduces degradation compared to conventional quantum dot solar cells. The shell-core nanowire structure has a bottom electrode, nanowires growing vertically from it, quantum dots on the nanowire surface, an outer shell layer, and top electrode. The nanowires and quantum dots form an inner core for electron transmission, separated by the shell for hole extraction. This prevents charge recombination between the electrodes. The core-shell nanowire array allows efficient electron and hole extraction while minimizing losses and corrosion compared to flat quantum dot layers.

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Solar cell with enhanced efficiency through selective hole transport through a quantum dot structure. The solar cell features a charge-selective emitter layer with a superlattice quantum dot structure that selectively passes electrons while allowing holes to pass through. This selective hole transport enables efficient separation of charge carriers, significantly reducing recombination losses and increasing overall solar cell efficiency.

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A method for preparing high-efficiency quantum dot solar cells by growing multilayer quantum dots on chamfered substrates. The chamfered substrate provides enhanced uniformity and control over the quantum dot growth process, while the chamfered surface inhibits dot migration. This approach enables precise control over the quantum dot layer thickness and distribution, leading to improved solar cell performance.

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A Schottky junction solar cell with enhanced efficiency through a novel epitaxial structure. The invention introduces a single-layer graphene layer between the InAs quantum dot array and the GaAs substrate, effectively preventing inter-diffusion between the quantum dots and the substrate. This structural modification enables improved interface quality, reduced defect density, and enhanced quantum dot stability, leading to higher conversion efficiency in solar cells.

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A quantum dot-based solar cell that achieves record-breaking power conversion efficiency (PCE) in infrared (IR) photovoltaics through a novel multi-bandgap quantum dot ensemble approach. The ensemble consists of semiconductor nanocrystals with different bandgaps, which are individually synthesized and then blended together in a solution. By carefully controlling the relative concentrations and bandgaps of the different nanocrystals, the ensemble can be engineered to absorb and convert IR light across the solar spectrum, resulting in a Voc of 0.4 V and Jsc of 3.7 mA/cm², surpassing previous records for both parameters. The ensemble's optical properties are optimized through band-filling and Fermi-level modulation, enabling efficient charge transport through low-defect-density pathways. This approach decouples the traditional Voc-Jsc trade-off, enabling the realization of high PCE values in IR photovoltaics.

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Quantum dot solar cells with improved photoelectric conversion efficiency through controlled aggregation and enhanced light absorption. The solar cells incorporate a ligand that can be well adsorbed to a photocathode and can be easily adjusted in length, enabling uniform distribution of quantum dots on the surface of the photocathode. The adsorbent is specifically designed to facilitate controlled aggregation of the quantum dots between the photocathode surface and the scattering layer, while maintaining optimal light absorption properties. This approach addresses the traditional limitations of quantum dot solar cells by enabling both uniform distribution of the quantum dots and controlled aggregation between the photocathode surface and the scattering layer.

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A solar cell design that enhances both absorption and charge transport efficiency through a novel photonic crystal structure. The device features a two-dimensional photonic crystal plate with a periodic lattice of nanorods, which is sandwiched between a graphene-based hybrid material layer containing quantum dots. The photonic crystal structure enhances absorption across the solar spectrum while the graphene layer provides efficient charge carrier transport between the quantum dots and electrodes. The design addresses stability concerns by eliminating organic components and incorporating inorganic materials that resist degradation in humid environments.

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All-solid-state solar cells based on simultaneous deposition of quantum dots and a novel preparation method achieve high efficiency, low cost, and stability through a novel device architecture. The solar cells employ quantum dots as light-absorbing materials, which are deposited simultaneously with the photovoltaic layer through a novel deposition process. This approach eliminates the need for organic solvents and high-temperature processing, while maintaining the quantum dot's inherent properties. The device architecture enables efficient charge carrier collection and transport, resulting in improved photovoltaic performance compared to conventional quantum dot solar cells.

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