1892 results about "Electron blocking layer" patented technology

The present invention generally relates to organic photosensitive optoelectronic devices. More specifically, it is directed to organic photovoltaic devices, e.g., organic solar cells. Further, it is directed to an optimized organic solar cell comprising multiple stacked subcells in series. High power conversion efficiency are achieved by fabrication of a photovoltaic cell comprising multiple stacked subcells with thickness optimization and employing an electron blocking layer.

A laser diode, grown on a miscut nonpolar or semipolar substrate, with lower threshold current density and longer stimulated emission wavelength, compared to conventional laser diode structures, wherein the laser diode's (1) n-type layers are grown in a nitrogen carrier gas, (2) quantum well layers and barrier layers are grown at a slower growth rate as compared to other device layers (enabling growth of the p-type layers at higher temperature), (3) high Al content electron blocking layer enables growth of layers above the active region at a higher temperature, and (4) asymmetric AlGaN SPSLS allowed growth of high Al containing p-AlGaN layers. Various other techniques were used to improve the conductivity of the p-type layers and minimize the contact resistance of the contact layer.

A group III nitride semiconductor light emitting device according to the present invention includes an immediate layer formed of AlxGa1-x-yInyN (0<x<1, 0<y<1, x+y<1) between an active layer and a cladding layer and an electron blocking layer formed of p-type group III nitride semiconductor having a smaller electron affinity than that of the intermediate layer so as to be in contact with the intermediate layer. The semiconductor light emitting layer may be a laser diode or a LED.

A nitride semiconductor laser device has a group III nitride semiconductor multilayer structure. The group III nitride semiconductor multilayer structure includes an n-type semiconductor layer, a p-type semiconductor layer and a light emitting layer held between the n-type semiconductor layer and the p-type semiconductor layer, and the p-type semiconductor layer is formed by successively stacking a p-side guide layer, a p-type electron blocking layer in contact with the p-side guide layer and a p-type cladding layer in contact with the p-type electron blocking layer from the side closer to the light emitting layer. The p-side guide layer is formed by stacking a layer made of a group III nitride semiconductor containing Al and a layer made of a group III nitride semiconductor containing no Al. The p-type cladding layer is made of a group III nitride semiconductor containing Al, and the p-type electron blocking layer is made of a group III nitride semiconductor having a larger Al composition than the p-type cladding layer.

The present invention generally relates to organic photosensitive optoelectronic devices. More specifically, it is directed to organic photovoltaic devices, e.g., organic solar cells. Further, it is directed to an optimized organic solar cell comprising multiple stacked subcells in series. High power conversion efficiency are achieved by fabrication of a photovoltaic cell comprising multiple stacked subcells with thickness optimization and employing an electron blocking layer.

The invention provides a quantum dot luminescent device. The quantum dot luminescent device comprises an anode, a hole transport layer, a quantum dot luminescent layer, an electronic transfer layer and a cathode which are arranged sequentially and adjacently. The quantum dot luminescent device further comprises an electronic barrier layer. The electronic barrier layer is arranged in the electronic transfer layer or between the quantum dot luminescent layer and the electronic transfer layer. Due to the arrangement of the electronic barrier layer, balance injection of charge carriers is ensured, automatic charge transfer between the electronic transfer layer and the quantum dot luminescent layer is isolated, electric neutrality of a quantum dot is ensured, then the quantum dot luminescent device can keep deserved luminous efficiency, the external quantum efficiency of the quantum dot luminescent device is improved, and meanwhile the service life of the quantum dot luminescent device is largely prolonged.

An organic photoelectric conversion element comprises: a pair of electrodes; an organic photoelectric conversion layer arranged between the pair of electrodes; and an positive hole blocking layer arranged between one of the pair of electrodes and the organic photoelectric conversion layer, wherein an ionization potential of the positive hole blocking layer is larger than a work function of the adjoining electrode by 1.3 eV or more, and wherein an electron affinity of the positive hole blocking layer is equal to or larger than that of the adjoining organic photoelectric conversion layer. An electron blocking layer may be arranged between the other one of the pair of electrodes and the organic photoelectric conversion layer, wherein its electron affinity is smaller than a work function of the adjoining electrode by 1.3 eV or more, and its ionization potential is equal to or smaller than that of the adjoining organic photoelectric conversion layer.

Methods and apparatuses for electronic devices such as non-volatile memory devices are described. The memory devices include a multi-layer control dielectric, such as a double or triple layer. The multi-layer control dielectric includes a combination of high-k dielectric materials such as aluminum oxide (Al2O3), hafnium oxide (HfO2), and / or hybrid films of hafnium aluminum oxide. The multi-layer control dielectric provides enhanced characteristics, including increased charge retention, enhanced memory program / erase window, improved reliability and stability, with feasibility for single or multistate (e.g., two, three or four bit) operation.

A photoelectric conversion device includes, in the following order: a first electrode; an electron blocking layer; a photoelectric conversion layer containing a merocyanine dye; a hole blocking layer; and a transparent electrode as a second electrode, and an absorption maximum wavelength in a thin film absorption spectrum of the photoelectric conversion layer containing a merocyanine dye is within a range of from 400 to 520 nm.

The present disclosure relates to photosensitive optoelectronic devices comprising at least one of an electron blocking or hole blocking layer. Further disclosed are methods of increasing power conversion efficiency in photosensitive optoelectronic devices using at least one of an electron blocking or hole blocking layer. The electron blocking and hole blocking layers presently disclosed may reduce electron leakage current by reducing the dark current components of photovoltaic cells. This work demonstrates the importance of reducing dark current to improve power conversion efficiency of photovoltaic cells.

The invention discloses a perovskite type electroluminescence device. The device comprises a substrate, a cathode, an electronic transmission-hole blocking layer, a luminescent layer, a hole transmission-electron blocking layer and an anode, wherein the luminescent layer is made of a material of a perovskite structure; the structure of the device can effectively promote injection and transmission of the charge carriers, restrict the sufficient recombination luminescence of the charge carriers / excitons, and adjust the emission color from the near ultraviolet light band, the visible light band to the near-infrared band by means of changing the components of the luminescent material. The electroluminescence device provided by the invention is high in efficiency, low in turn-on voltage, excellent in color saturation and stable in spectrum changed along with the voltage, meanwhile, the perovskite type electroluminescence device is simple in process, low in cost and is suitable for being widely used in the products of the display and illumination field, in particular suitable for the large-sized industrial production of the high-performance electroluminescence devices with low cost and flexible substrate.

The present invention, in one aspect, relates to a solar cell. In one embodiment, the solar cell includes an anode; an active organic layer comprising an electron-donating organic material and an electron-accepting organic material; a semiconducting layer formed between the anode and the active organic layer; and an electron-blocking layer (EBL) formed between the semiconducting layer and the active organic layer, where the EBL is transparent and adapted for blocking electron leakage from the active organic layer to the anode while transporting holes from the active organic layer to the anode.

An organic light-emitting device includes: a first electrode, a second electrode facing the first electrode, a phosphorescent emission layer between the first electrode and the second electrode, an electron transportation layer between the phosphorescent emission layer and the second electrode, an electron control layer between the phosphorescent emission layer and the electron transportation layer, and an electron blocking layer between the phosphorescent emission layer and the first electrode. An organic light-emitting display apparatus includes the organic light-emitting device.

Methods and apparatuses for electronic devices such as non-volatile memory devices are described. The memory devices include a multi-layer control dielectric, such as a double or triple layer. The multi-layer control dielectric includes a combination of high-k dielectric materials such as aluminum oxide, hafnium oxide, and / or hybrid films of hafnium aluminum oxide. The multi-layer control dielectric provides enhanced characteristics, including increased charge retention, enhanced memory program / erase window, improved reliability and stability, with feasibility for single or multi state (e.g., two, three or four bit) operation.

The invention discloses an ultraviolet-light gallium nitride semiconductor light emitting diode with gradient electron barrier layers. By means of energy band engineering design and optimization, six kinds of superlattice-like AlGaN electron barrier layers with different changing types are introduced to an epitaxial structure of the light-emitting diode so as to realize the change of an aluminum component, so that the polarization effect in the electron barrier layers is changed, and high hole injection is realized so as to solve the problems of low P-type doping efficiency and insufficient hole concentration in the ultraviolet-light semiconductor light emitting diode.

A semiconductor device comprises an active layer and a cladding layer. An electron blocking layer is at least partially disposed in a region between the active layer and the cladding layer and is configured to form a potential barrier to a flow of electrons from the active layer toward the cladding layer. The electron blocking layer comprises two elements from Group III of the periodic table and an element from Group V of the periodic table. One of the two elements from Group III of the periodic table has a concentration profile with a first portion that gradually increases in concentration in a direction away from the active layer toward the cladding layer and a second portion that gradually decreases in concentration between the first portion and the cladding layer.

An organic electroluminescent device with the feature of three-wavelength luminescence is provided. The device includes a hole transporting layer, an electron blocking layer, a first host material layer, a second host material layer, a hole blocking layer, and an electron transporting layer placed between an anode and a cathode in turn. In which, the first host material layer has a first guest luminous substance mixed therein for projecting a first color light source (B), while the second host material layer correspondingly has a second guest luminous substance and a third guest luminous substance mixed therein for projecting a second color light source (G) and a third color light source (R), respectively, under the effect of an external bias voltage, wherein said second guest luminous substance or said third guest luminous substance may be a phosphorescence substance. Thus, not only a continuously full-band, full-colored light source featuring three-wavelength may be acquired directly by means of the combination of RGB colors, but also an effective utilization of phosphorescence substance and thus significantly raised luminescence efficiency may be obtained.

The invention discloses a mesoscopic solar cell based on a perovskite-kind light absorption material. The mesoscopic solar cell comprises a glass substrate, a transparent conductive layer, a hole blocking layer, an electron transport layer and a back electrode; and the hole blocking layer is a compact layer, the electron transport layer is a porous thin film, a porous electron blocking layer is further disposed between the electron transport layer and the back electrode, and the electron transport layer and the electron blocking layer are filled with the perovskite-kind light absorption material. Or the mesoscopic solar cell comprises a glass substrate, a transparent conductive layer, a hole transport layer and a back electrode; and the hole transport layer is a porous thin film, a compact electron blocking layer is further disposed between the hole transport layer and the transparent conductive layer, and the hole transport layer is filled with the perovskite-kind light absorption material. The invention further discloses a preparation method of the mesoscopic solar cell. The cell has optimized structure, the filled perovskite material in mesoporous is more, morphology is good, charge transmission performance is improved, cell photoelectric conversion efficiency is greatly improved, and long-term illumination stability of the cell is substantially improved.

A solar cell having at least one hole blocking layer and at least one electron blocking layer, and methods of fabricating such devices. Specifically, a hole blocking layer is disposed between a first electrode of the solar cell and the active layer. Further, an electron blocking layer is disposed between a second electrode and the active layer. The solar cell may be formed by fabricating an anode component and a cathode component and laminating the anode component and the cathode component together.

The invention relates to an LED structure with an aluminum-component-gradient electron blocking layer. Low-Al-component AlxGa1-xN is arranged on one side, which is in contract with an outer GaN barrier of a multiple-quantum well layer, of the aluminum-component-gradient electron blocking layer, the x is greater than or equal to 0 and smaller than or equal to 0.1, high-Al-component AlyGa1-yN is arranged on one side, which is in contact with a p-GaN layer, of the aluminum-component-gradient electron blocking layer, the y is greater than 0.1 and is smaller than or equal to 0.4, and the quantity of Al components in the middle of the aluminum-component-gradient electron blocking layer is gradually increased linearly. The low-Al-component AlGaN is arranged on one side, which is in contact with the GaN barrier, of the electron blocking layer, so that the density of polarization charges between interfaces of the electron blocking layer and the GaN barrier are effectively reduced, and a polarization field is weakened. Accordingly, the concentration of two-dimensional electron gas of the interfaces is greatly reduced, leakage current is decreased, the internal quantum efficiency of a device is improved in general, and the problem of attenuation of the quantum efficiency is solved.

The invention relates to a novel semiconductor light-emitting diode, which comprises a substrate, a buffer layer, an N-type layer, an active layer, an electronic barrier layer, a P-type layer and a P-type contact metal layer. The P-type layer, the electronic barrier layer, the active layer and the like are penetrated through etching; an N-type layer material is exposed to one side of a P-type material directly, and an N-type contact metal and an electrode are covered on an exposed area, so that the diffusion of transverse current in the N-type layer is enhanced; and simultaneously, a P-type metal covers an integral P-type semiconductor layer, and an LED emits light from the bottom surface of the substrate. Through the improvement, the transverse diffusion distance of the current in LED devices is shortened substantially, uneven distribution of current density in the LED devices due to current congestion is prevented, so that the LED devices emit the light uniformly, and the shading effect of a P-type electrode is eliminated.

The invention discloses a GaN-based VCSEL chip based on a porous DBR. The GaN-based VCSEL chip comprises a substrate, a buffer layer manufactured on the substrate, a bottom porous DBR layer manufactured on the buffer layer, an n-type doped GaN layer manufactured on the bottom porous DBR layer, an active layer manufactured on the n-type doped GaN layer, an electron blocking layer manufactured on the active layer, a p-type doped GaN layer manufactured on the electron blocking layer, a current limiting layer manufactured on the p-type doped GaN layer, a transparent electrode manufactured on the p-type doped GaN layer, an n electrode, a p electrode manufactured on the transparent electrode, and a dielectric DBR layer, wherein a table board is formed by etching the periphery of the n-type doped GaN layer downwards; a current window is formed in the center of the current limiting layer; the current limiting layer covers the active layer, the electron blocking layer and the side wall of a bulge part of the n-type doped GaN layer; the n electrode is manufactured on the table board of the n-type doped GaN layer; a notch is formed in the middle of the p electrode; and the dielectric DBR layer is manufactured on the transparent electrode in the notch of the p electrode.

The invention discloses a quantum dot electroluminescent device and a preparation method thereof. The device comprises a first electrode layer, a second electrode layer as well as a hole injection layer, a hole transmission layer, an electron barrier layer, a quantum dot luminescent layer, a hole barrier layer and an electron transmission layer, wherein the hole injection layer, the hole transmission layer, the electron barrier layer, the quantum dot luminescent layer, the hole barrier layer and the electron transmission layer are sandwiched between the two electrode layers. The preparation method is characterized in that the electron barrier layer covers the hole transmission layer by utilizing a rotary coating method; the material of the electron barrier layer is preferably DNA-CTMA (deoxyribonucleic acid-cetyltrimethyl ammonium), thus the effective hole injection and efficient electron barrier are realized, and the device performances and luminescent color purity are improved greatly.

A method for forming a color organic light-emitting device including depositing a first electrode over a substrate; depositing a first emissive layer over the first electrode for producing a first colored light in response to hole-electron recombination; and selectively patternwise depositing a hole-blocking layer over the first emissive layer. The method also includes depositing a second emissive layer over the hole-blocking layer which in response to hole-electron recombination emits colored light different from the colored light emitted from the first emissive layer; depositing a second electrode over the second emissive layer; and whereby the patternwise deposition of the hole-blocking layer has been selected to substantially shift hole-electron recombination from the second to the first emissive layers.

Light emitting devices having charge transporting layers comprising one or more metal complexes are provided. More particularly, devices include hole transporting layers comprising at least one metal complex are disclosed. The present devices can further comprise an electron blocking layer for improved efficiency.

The invention discloses a light-emitting diode epitaxial wafer and a preparation method thereof, and belongs to the technical field of semiconductors. The light-emitting diode epitaxial wafer comprises a sapphire substrate, a low-temperature buffer layer, a high-temperature non-doped GaN layer, a first defect barrier layer, an N-type GaN layer, a stress release layer, a multi-quantum well layer, a P-type electron blocking layer, a P-type GaN layer and a P-type contact layer, wherein the low-temperature buffer layer, the high-temperature non-doped GaN layer, the first defect barrier layer, the N-type GaN layer, the stress release layer, the multi-quantum well layer, the P-type electron blocking layer, the P-type GaN layer and the P-type contact layer are sequentially laminated on the sapphire substrate; a second defect barrier layer is inserted into the N-type GaN layer; the first defect barrier layer comprises alternately laminated AlGaN layers and GaN layers; the second defect barrier layer comprises alternately laminated SiN films and N-type AlGaN layers; and the stress release layer comprises alternately laminated InGaN layers and GaN layers. According to the light-emitting diode epitaxial wafer, extension of defects formed by lattice mismatch into the multi-quantum well layer is effectively suppressed; stress release is enhanced; the crystal quality is improved; leakage passages are reduced; the anti-static electricity capacity of an LED chip is improved; and the product yield is improved.

A light-emitting device having an n-type semiconductor layer having a plurality of pits with planar regions between the pits, the pits being characterized by sidewalk that intersect the planar regions is disclosed. A plurality of alternating sub-layers of materials having different bandgaps is deposited on the n-type semiconductor layer. The sub-layers have thicknesses such that the sub-layers form an active layer in the planar regions between the pits and a super lattice on the sidewalls of the pits. A p-type semiconductor layer is deposited on the plurality of alternating sub-layers. One of the sub-layers includes an electron blocking layer. The electron blocking layer is characterized by a first thickness in the substantially planar regions and a second thickness in areas adjacent to the sidewalls of the pits, the second thickness being less than the first thickness.

An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The p-type contact layer and electron blocking layer can be doped with a p-type dopant. The dopant concentration for the electron blocking layer can be at most ten percent the dopant concentration of the p-type contact layer. A method of designing such a heterostructure is also described.

The invention discloses a gallium-nitride-based light emitting diode capable of improving electron injection efficiency. The gallium-nitride-based light emitting diode comprises a substrate, a gallium nitride nucleation layer, a buffer layer, an n-type contact layer, a lower multicycle n-type electron coupling layer, a lower tunneling potential barrier layer, an upper multicycle n-type electron coupling layer, an upper tunneling potential barrier layer, a multicycle active luminous layer, a negative electrode, a p-type electron blocking layer, a p-type contact layer and a positive electrode, wherein the gallium nitride nucleation layer is manufactured on the substrate; the buffer layer is manufactured on the gallium nitride nucleation layer; the n-type contact layer is manufactured on the buffer layer; a table top is formed on one side of the upper surface of the n-type contact layer; the lower multicycle n-type electron coupling layer is manufactured on the other side of the table top on the n-type contact layer; the lower tunneling potential barrier layer is manufactured on the lower multicycle n-type electron coupling layer; the upper multicycle n-type electron coupling layer is manufactured on the lower tunneling potential barrier layer; the upper tunneling potential barrier layer is manufactured on the upper multicycle n-type electron coupling layer; the multicycle active luminous layer is manufactured on the upper tunneling potential barrier layer; the negative electrode is manufactured on the table top of the n-type contact layer; the p-type electron blocking layer is manufactured on the multicycle active luminous layer; the p-type contact layer is manufactured on the p-type electron blocking layer; and the positive electrode is manufactured on the p-type contact layer to form the structure of the gallium-nitride-based light emitting diode.

The invention provides a nitride light-emitting diode (LED) epitaxial wafer and a growing method thereof and relates to the technical field of semiconductor optoelectronics. The nitride LED epitaxial wafer structurally and sequentially comprises a substrate, a low-temperature buffer layer, an unintentionally doped GaN, an N-shaped electron-injection layer, an InGaN / GaN inserting layer, an active area, an electron blocking layer, a u-GaN / p-GaN superlattice and a p-GaN hole-injection layer from bottom to top. The InGaN / GaN inserting layer is grown between the N-shaped electron-injection layer and the active area so as to effective relieve stress of the active area, lower polarization electric fields, reduce limitation of stark effect through a quantum well, and improve luminance and anti-static properties. The u-GaN / p-GaN superlattice is inserted between the electron blocking layer and the P-shaped hole-injection layer so as to improve current expansion capacity and lower chip operating voltage.