48results about How to "Reduce carrier recombination" patented technology

Novel structures of photovoltaic cells (also called as solar cells) are provided. The Cells are based on the micro (or nano) structures which could not only increase the surface area but also have the capability of self concentrating the solar spectrum incident onto the cell. These photovoltaic cells have large power generation capability per unit physical area over the conventional cells. These cells will have enormous applications such as in space, in commercial, residential and industrial applications.

In a photoelectric conversion device, in a contact between a p-type semiconductor 3a and an electrode 2, an n-type semiconductor 6 of a conductivity type opposite to that of the p-type semiconductor is provided between the p-type semiconductor 3a and the electrode 2. The existence of the n-type semiconductor 6 allows a recombination rate of photo-generated carriers excited by incident light to be effectively reduced, and allows a dark current component to be effectively prevented from being produced. Therefore, it is possible to improve photoelectric conversion efficiency as well as to stabilize characteristics. Further, a tunnel junction is realized by increasing the concentration of a doping element in at least one or preferably both of the p-type semiconductor 3a and the n-type semiconductor 6 in a region where they are in contact with each other, thereby keeping ohmic characteristics between the semiconductor and the electrode good.

Novel structures of photovoltaic cells (also treated as solar cells) are provided. The cells are based on nanometer or micrometer-scaled wires, tubes, and/or rods, which are made of electronic materials covering semiconductors, insulators, and may be metallic in structure. These photovoltaic cells have large power generation capability per unit physical area over the conventional cells. These cells will have enormous applications such as in space, commercial, residential and industrial applications.

In a back-surface electrode type photoelectric conversion element having electrodes and semiconductor layers for collecting carriers disposed only on a back surface side of a semiconductor substrate, a semiconductor thin film that is larger in band gap than the semiconductor substrate and that contains an element causing a conductivity identical to or different from a conductivity of the semiconductor substrate is provided on a light-receiving surface side of the semiconductor substrate, and a diffusion layer is formed on a surface of the semiconductor substrate. Alternatively, 95% or more of light beams having a wavelength of anywhere from 800 nm to 2000 nm are caused to penetrate the light-receiving surface side of the semiconductor substrate, and an insulative thin film containing an element causing a conductivity identical to or different from the conductivity of the semiconductor substrate is provided so as to form a diffusion layer on the surface of the semiconductor substrate through diffusion of the element.

Novel structures of photovoltaic cells (also called as solar cells) are provided. The cells are based on nanoparticles or nanometer-scaled wires, tubes, and/or rods, which are made of electronic materials covering semiconductors, insulators, and may be metallic in structure. These photovoltaic cells have large power generation capability per unit physical area over the conventional cells. These cells will have enormous applications such as in space, commercial, residential and industrial applications.

A back contact single heterojunction solar cell and associated fabrication process are provided. A first semiconductor substrate is provided, lightly doped with a first dopant type. The substrate has a first energy bandgap. A second semiconductor is formed over a region of the substrate backside. The second semiconductor has a second energy bandgap, larger than the first energy bandgap. A third semiconductor layer is formed over the first semiconductor substrate topside, moderately doped with the first dopant and textured. An emitter is formed in the substrate backside, heavily doped with a second dopant type, opposite of the first dopant type, and a base is formed in the substrate backside, heavily doped with the first dopant type. Electrical contacts are made to the base and emitter. Either the emitter or base is formed in the second semiconductor.

Novel structures of photovoltaic cells (also treated as solar cells) are provided. The cells are based on nanometer-scaled wires, tubes, and/or rods, which are made of electronic materials covering semiconductors, insulators or metallic in structure. These photovoltaic cells have large power generation capability per unit physical area over the conventional cells. These cells will have enormous applications in space, commercial, residential, and industrial applications.

One embodiment of the present invention provides a semiconductor light-emitting device, which comprises: an upper cladding layer; a lower cladding layer; an active layer between the upper and lower cladding layers; an upper ohmic-contact layer forming a conductive path to the upper cladding layer; and a lower ohmic-contact layer forming a conductive path the lower cladding layer. The lower ohmic-contact layer has a shape substantially different from the shape of the upper ohmic-contact layer, thereby diverting a carrier flow away from a portion of the active layer which is substantially below the upper ohmic-contact layer when a voltage is applied to the upper and lower ohmic-contact layers.

A backside illuminated image sensor comprises a sensor layer implementing a plurality of photosensitive elements of a pixel array, an oxide layer adjacent a backside surface of the sensor layer, and at least one dielectric layer adjacent a frontside surface of the sensor layer. The sensor layer further comprises a plurality of backside trenches formed in the backside surface of the sensor layer and arranged to provide isolation between respective pairs of the photosensitive elements. The backside trenches have corresponding backside field isolation implant regions formed in the sensor layer, and the resulting structure provides reductions in carrier recombination and crosstalk between adjacent photosensitive elements. The image sensor may be implemented in a digital camera or other type of digital imaging device.

A bifacial solar cell including a semiconductor substrate of a first conductivity type, a fixed charge layer, a first grid electrode, a semiconductor layer of a second conductivity type and a second grid electrode are provided. The fixed charge layer is located on a rear surface of the semiconductor substrate. The first grid electrode is located over the rear surface of the semiconductor substrate and electrically connected to the rear surface of the semiconductor substrate by penetrating through the fixed charge layer. The semiconductor layer is located on the front surface of the semiconductor layer. The second grid electrode is located over and electrically connected to the semiconductor layer.

A solar cell unit comprising a strip plate which has a third surface and a fourth surface opposite to the third surface, wherein a third doping region and a fourth doping region are arranged on the third surface and the fourth surface respectively, and a first doping region and a second doping region are arranged on side surfaces adjacent to the third surface and the fourth surface respectively; the types of impurities in the third doping region and the fourth doping region are contrary to one another; the surfaces of the first doping region and the second doping region have uniform doping type. Accordingly, the present invention further provides a method for manufacturing a solar cell unit.

The invention relates to a graphene photoelectric detector based on an interdigital electrode structure. The photoelectric detector comprises a substrate layer and an optical waveguide disposed on thesubstrate layer. The optical waveguide is provided with a dielectric isolation layer; the dielectric isolation layer is provided with two metal layers which are not in contact with each other; the two metal layers serve as electrodes; graphene layers are arranged on the two metal layers; and the graphene layers serve as light absorption layers. The provided graphene photoelectric detector based on the interdigital electrode is compatible with a CMOS process and has high performance.

This invention relates to a novel structure of photovoltaic devices (e.g. photovoltaic cells also called as solar cells) are provided. The cells are based on the micro or nano scaled structures which could not only increase the surface area but also have the capability of reducing the reflection and increasing the absorption of incident light. More specifically, the structures are based on 3D structure which are made of electric materials covering semiconductors, insulators, dielectric, polymer, and metallic type materials. By using such structures reflection loss of the light from the cell is significantly reduced, increasing the absorption, which results in increasing the conversion efficiency of the solar cell, and reducing the usage of material while increasing the flexibility of the solar cell. The structures can be also used in other optical devices wherein the reflection loss and absorption are required to enhance significantly improve the device performances.

The invention discloses a method for preparing a single-crystal silicon texture-surface structure with low reflectivity. A large amount of tetrahedral pyramids are formed on a surface of a silicon wafer by a traditional method, and many nanometer pores are formed in the surface of the silicon wafer by immersion processing of an alkali alcohol solution. The reflectivity of the surface of the silicon wafer with a nanometer structure in a pyramid shape can be further reduced; and meanwhile, the carrier recombination of the surface of the silicon wafer is only reduced slightly, almost no influence on the lifetime of a minority carrier of the silicon wafer is generated, so that the photoelectric conversion efficiency of a crystalline silicon solar cell can be effectively improved.

Novel structures of photovoltaic cells (also treated as solar cells) are provided. The cells are based on nanometer-scaled wires, tubes, and/or rods, which are made of electronic materials covering semiconductors, insulators or metallic in structure. These photovoltaic cells have large power generation capability per unit physical area over the conventional cells. These cells will have enormous applications in space, commercial, residential, and industrial applications.

A photoelectric conversion device with low resistance loss and high conversion efficiency is provided. The photoelectric conversion device includes a first silicon semiconductor layer and a second silicon semiconductor layer between a pair of electrodes. The first silicon semiconductor layer is provided over one surface of a crystalline silicon substrate having one conductivity type and has a conductivity type opposite to that of the crystalline silicon substrate, and the second silicon semiconductor layer is provided on the other surface of the crystalline silicon substrate and has a conductivity type which is the same as that of the crystalline silicon substrate. Further, the first silicon semiconductor layer and the second silicon semiconductor layer each have a carrier concentration varying in the film thickness direction.