Abstract: A display substrate including: a base substrate with a display region, an encapsulation region and an edge region on a periphery of the encapsulation region, the edge region includes a bonding region on at least one side of the base substrate; a plurality of stacked inorganic film layers on a side of the base substrate; a plurality of first grooves, at the edge region, spaced apart from each other in a direction distal from the encapsulation region, and extending along a periphery of the base substrate, at least one of the plurality of first groove runs through at least one inorganic film layer of the plurality of inorganic film layers, and a distance between each first groove and the display region is larger than that between each first groove and an edge of the base substrate; and an organic layer.

Abstract: A display device includes an optical module, a light emitting structure, a lower substrate including a display area, and in order within the display area a first area corresponding to the optical module, second area adjacent to the optical module, and a third area including the light emitting structure, a light-transmitting filling layer in the first area and corresponding to the optical module, a light blocking layer in the second area and defining an opening corresponding to the light-transmitting filling layer in the first area, and an upper substrate facing the lower substrate with the light emitting structure and the light blocking layer therebetween.

Abstract: A display apparatus includes a substrate having a bending region between a first region and a second region, the bending region being configured to be bent about a bending axis that extends in one direction; a display unit on the substrate; a first wiring unit at the bending region, the first wiring unit including a first bending portion having a plurality of first holes; and a second wiring unit spaced apart from the first wiring unit and at the bending region, the second wiring unit including a second bending portion having a different shape from the first bending portion.

Abstract: A display device with high design flexibility is provided. The display device includes a display element, a touch sensor, and a transistor between two flexible substrates. An external electrode that supplies a signal to the display element and an external electrode that supplies a signal to the touch sensor are connected from the same surface of one of the substrates.

Abstract: An organic light emitting diode (OLED) display panel and a method of fabricating the same are provided. The OLED display panel includes a double-layer polyimide flexible layer, a thin film transistor driving layer, an OLED light emitting layer, and a thin film encapsulation layer. The double-layer polyimide flexible layer includes a glass substrate, a wetting layer, a polyimide flexible layer, and an inorganic silicon nitride layer. The wetting layer converts the glass substrate or the inorganic silicon nitride layer from hydrophilic to hydrophobic.

Abstract: A flexible touch panel is provided. Both reduction in thickness and high sensitivity of a touch panel are achieved. The touch panel includes a first flexible substrate, a first insulating layer over the first substrate, a transistor and a light-emitting element over the first insulating layer, a color filter over the light-emitting element, a pair of sensor electrodes over the color filter, a second insulating layer over the sensor electrodes, a second flexible substrate over the second insulating layer, and a protective layer over the second substrate. A first bonding layer is between the light-emitting element and the color filter. The thickness of the first substrate and the second substrate is each 1 ?m to 200 ?m inclusive. The first bonding layer includes a region with a thickness of 50 nm to 10 ?m inclusive.

Abstract: A method for manufacturing an organic light emitting device includes: forming an organic light emitting display panel including a substrate provided on a support substrate, an organic light emitting element on the substrate, and a thin film encapsulating film covering the organic light emitting element; detaching the support substrate from the organic light emitting display panel; attaching a bottom protecting film to a bottom of the organic light emitting display panel, the bottom protecting film comprising a first electricity removing layer configured to remove static electricity; and cutting the organic light emitting display panel into a plurality of organic light emitting devices.

Abstract: An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.

Abstract: Provided is an electronic device containing: a two-dimensional semiconductor material; and another heterogeneous material adjacent to the two-dimensional semiconductor material, wherein the heterogeneous material is doped with an impurity of a type different from the two-dimensional semiconductor material or has a band gap different from the two-dimensional semiconductor material.

Abstract: A transistor display panel according to an exemplary embodiment includes: a substrate; a first transistor disposed on the substrate; and a pixel electrode connected to the first transistor, wherein the first transistor includes a lower electrode disposed on the substrate, a first semiconductor overlapping the lower electrode, a first insulating layer covering the first semiconductor, a first gate electrode disposed on the first insulating layer and overlapping the first semiconductor, and a first source connecting member and a first drain connecting member disposed on the same layer as the first gate electrode and connected to the first semiconductor, wherein the first gate electrode is formed as a triple layer, the first source connecting member and first drain connecting member are formed as a double layer, and the first source connecting member is connected to the lower electrode.

Abstract: The present invention provides a method of manufacturing an organic device having a protective film, the method including: providing bonding layers (adhesives) on one surface of a first substrate and one surface of a second substrate; providing an organic device on the other surface of the first substrate; and providing the second substrate on the organic device such that the bonding layer (adhesive) provided on the second substrate is in contact with the organic device. Since the organic device having the protective film according to the present invention may be attached to other materials through the bonding layer (adhesive), it is not necessary to apply heat in order to attach the organic device to other materials, and as a result, it is possible to attach the organic device to various materials having various shapes regardless of types and shapes of materials.

Abstract: A substrate for a display device and a display device including the same are disclosed. The substrate includes a first thin-film transistor including an oxide semiconductor layer, a second thin-film transistor spaced apart from the first thin-film transistor and including a polycrystalline semiconductor layer, and a storage capacitor including at least two storage electrodes. One of the at least two storage electrodes is located in the same layer and is formed of the same material as a gate electrode of the second thin-film transistor that is disposed under the polycrystalline semiconductor layer, and another one of the at least two storage electrodes is located above the polycrystalline semiconductor layer with at least one insulation film interposed therebetween. Accordingly, lower power consumption and a larger area of the substrate are realized.

Abstract: A method for manufacturing a semiconductor device structure is provided. The method includes providing a base substrate and forming a buffer layer on the base substrate. The method also includes forming a patterned silicon layer on the buffer layer. The patterned silicon layer has an opening to expose a portion of the buffer layer. The method further includes epitaxially growing a patterned channel layer and a patterned barrier layer on a top surface of the patterned silicon layer sequentially. In addition, the method includes forming a gate electrode on the patterned barrier layer.

Abstract: To provide a method of manufacturing an optical film formed on a plastic substrate. There is provided a method of manufacturing an optical film including the steps of laminating a separation layer and an optical filter on a first substrate, separating the optical filter from the first substrate, attaching the optical filter to a second substrate. Since the optical film manufactured according to the invention has flexibility, it can be provided on a portion or a display device having a curved surface. Further, the optical film is not processed at high temperatures, and hence, an optical film having high yield with high reliability can be formed. Furthermore, an optical film having an excellent impact resistance property can be formed.

Abstract: The present invention provides a flexible organic light-emitting diode (OLED) display panel, which includes a first polyimide layer, a barrier layer and a second polyimide layer that are sequentially stacked and a thin film transistor (TFT) structure and an OLED structure that are sequentially disposed on the second polyimide layer, in which a material of the barrier layer includes at least one of silicon dioxide and silicon nitride. By arranging a flexible base as an upper polyimide layer and a lower polyimide layer and adding a barrier layer between the two polyimide layers, the present invention can effectively block water and oxygen from entering an interior of a component through a flexible polyimide base, thereby protecting the TFT structure and the OLED structure and improving the lifespan of the OLED display panel. The present invention further provides a manufacturing method of a flexible OLED display panel.

Abstract: The disclosed invention relates to a semiconductor light-emitting element comprising: a plurality of semiconductor layers which are provided with a growth substrate eliminating surface on the side where a first semiconductor layer is located; a support substrate which is provided with a first electrical pathway and a second electrical pathway; a joining layer which joins a first surface side of the support substrate with a second semiconductor layer side of the plurality of semiconductor layers, and is electrically linked with the first electrical pathway; a joining layer eliminating surface which is formed on the first surface, and in which the second electrical pathway is exposed, and which is open towards the plurality of semiconductor layers; and an electrical link for electrically linking the plurality of semiconductor layers with the second electrical pathway exposed in the joining layer eliminating surface.

Abstract: A light emitting diode including an n-doped InXnGa(1-Xn)N layer and a p-doped InXpGa(1-Xp)N layer, and an active area arranged between the InXnGa(1-Xn)N layer and the InXpGa(1-Xp)N layer including: a first InN layer with a thickness eInN106; a second InN layer with a thickness eInN108; a separating layer arranged between the InN layers and including InXbGa(1-Xb)N and a thickness <3 nm; an InX1Ga(1-X1)N layer arranged between the InXnGa(1-Xn)N layer and the first InN layer; an InX2Ga(1-X2)N layer arranged between the InXpGa(1-Xp)N layer and the second InN layer; wherein the indium compositions Xn, Xp, Xb, X1 and X2 are between 0 and about 0.25, and wherein the thicknesses eInN106 and eInN108 are such that eInN106<eInN108.

Abstract: A light emitting diode includes a first electrode, a second electrode, and an epitaxial structure. The epitaxial structure is arranged on the first electrode, and electrically connects with the first electrode and the second electrode. The second electrode surrounds periphery of the epitaxial structure to reflect light from the epitaxial structure out from the top of the epitaxial structure. A method for manufacturing the light emitting diode is also presented. The light emitting diode and the method increase lighting efficiency of the light emitting diode.

Abstract: A GaN-based power electronic device and a method for manufacturing the same is provided. The GaN-based power electronic device comprising a substrate and an epitaxial layer over the substrate. The epitaxial layer comprises a GaN-based heterostructure layer, a superlattice structure layer and a P-type cap layer. The superlattice structure layer is provided over the heterostructure layer, and the P-type cap layer is provided over the superlattice structure layer. By using this electronic device, gate voltage swing and safe gate voltage range of the GaN-based power electronic device manufactured on the basis of the P-type cap layer technique may be further extended, and dynamic characteristics of the device may be improved. Therefore, application process for the GaN-based power electronic device that is based on the P-type cap layer technique will be promoted.

Abstract: The present invention provides a light emitting device which emit light having a high-order level without increasing a current injection density to an active layer. A light emitting device according to the present invention includes an upper electrode layer, a lower electrode layer, and an active layer provided between them. In this case, light is emitted by injection of electric current to the active layer through the upper electrode layer and the lower electrode layer, the active layer has a plurality of quantum-confined structures, and a first quantum-confined structure has a ground level having an energy level E0 and a high-order level having an energy level E1, and a second quantum-confined structure has an energy level E2 which is higher than the E0, and the E1 and the E2 are substantially matched.

Abstract: Provided is a method for manufacturing an organic EL device, including: a vapor deposition step of forming an organic layer over a substrate moving relative to a nozzle by discharging a vaporized organic layer-forming material through the nozzle. The vapor deposition step is performed so that a light emitting region formed of the organic layer and having a width A (mm) in a direction perpendicular to a direction in which the substrate is moving is formed, and so that W?A+2×h (where h?5 mm) is satisfied, where a length of an opening of the nozzle in the direction perpendicular to the direction in which the substrate is moving is denoted by W (mm), and a distance between the opening and the substrate is denoted by h (mm).

Abstract: The present invention relates generally to high current density access devices (ADs), and more particularly, to a structure and method of forming tunable voltage margin access diodes in phase change memory (PCM) blocks using layers of copper-containing mixed ionic-electronic conduction (MIEC) materials. Embodiments of the present invention may use layers MIEC material to form an access device that can supply high current-densities and operate reliably while being fabricated at temperatures that are compatible with standard BEOL processing. By varying the deposition technique and amount of MIEC material used, the voltage margin (i.e. the voltage at which the device turns on and the current is above the noise floor) of the access device may be tuned to specific operating conditions of different memory devices.

Abstract: A method for manufacturing a display device is provided. The method includes: forming, between a first substrate and a second substrate, a light-emitting element including an electroluminescence layer and a wiring over which a peeling layer formed by using the material of the electroluminescence layer is provided; and peeling whole of the second substrate from the first substrate so that the peeling layer over the wiring is simultaneously exposed.

Abstract: The present invention relates generally to high current density access devices (ADs), and more particularly, to a structure and method of forming tunable voltage margin access diodes in phase change memory (PCM) blocks using layers of copper-containing mixed ionic-electronic conduction (MIEC) materials. Embodiments of the present invention may use layers MIEC material to form an access device that can supply high current-densities and operate reliably while being fabricated at temperatures that are compatible with standard BEOL processing. By varying the deposition technique and amount of MIEC material used, the voltage margin (i.e. the voltage at which the device turns on and the current is above the noise floor) of the access device may be tuned to specific operating conditions of different memory devices.

Abstract: This invention provides a high-efficiency light-emitting device and the manufacturing method thereof The high-efficiency light-emitting device includes a substrate; a reflective layer; a bonding layer; a first semiconductor layer; an active layer; and a second semiconductor layer formed on the active layer. The second semiconductor layer includes a first surface having a first lower region and a first higher region.

Abstract: A light emitting diode includes a semiconductor stacked structure, a substrate, a first electrode, a second electrode and a third electrode. The semiconductor stacked structure includes a first semiconductor layer, a second semiconductor layer and a light emitting layer. An undoped semiconductor layer over the first semiconductor layer may be not removed or not completely removed to increase the strength of the semiconductor stacked structure and improve the reliability of the LED and the production yields of manufacturing process. A roughened structure (or a photonic crystal) can be formed on the undoped semiconductor layer when the semiconductor stacked structure to improve the light emitting efficiency of the LED.

Abstract: Provided is an organic light-emitting diode (OLED) display including: first and second plastic layers; a first barrier layer and a first intermediate layer each positioned between the first and second plastic layers; and an OLED layer formed on the second plastic layer. The first barrier layer comprises silicon nitride.

Abstract: Exemplary embodiments of the present invention disclose a light emitting diode including an n-type contact layer doped with silicon, a p-type contact layer, an active region disposed between the n-type contact layer and the p-type contact layer, a superlattice layer disposed between the n-type contact layer and the active region, the superlattice layer including a plurality of layers, an undoped intermediate layer disposed between the superlattice layer and the n-type contact layer, and an electron reinforcing layer disposed between the undoped intermediate layer and the superlattice layer. Only a final layer of the superlattice layer closest to the active region is doped with silicon, and the silicon doping concentration of the final layer is higher than that of the n-type contact layer.

Abstract: A method of manufacturing a semiconductor device includes grinding a back side of a substrate; and forming a nitride semiconductor layer on a front side of the substrate after the grinding. Compressive stress is generated in the nitride semiconductor layer that is formed.

Abstract: A light emitting device (10) comprises a body (11) comprising a substrate (12) of a p-type semiconductor material. The substrate has an upper surface (14) and having formed therein on one side of the upper surface and according to a bulk semi-conductor fabrication process utilizing lateral active area isolation techniques: a first n+-type island (16) to form a first junction (24) between the first island and the substrate; and a second n+-type island (18) spaced laterally from the first island (16). The substrate provides a laterally extending link (20) between the islands having an upper surface. The upper surface of the link, an upper surface of the island (16) and an upper surface of the island (18) collectively form a planar interface (21) between the body (11) and an isolation layer (19) of the device. The device comprises a terminal arrangement to apply a reverse bias to the first junction, to cause the device to emit light. The device is configured to facilitate the transmission of the emitted light.

Abstract: A method for manufacturing a deep isolation trench (221) and a method for manufacturing a high-voltage LED chip. Steps of the method for manufacturing a deep isolation trench (221) are as follows: forming a mask layer (202) on a substrate (200), and forming, in the mask layer, through etching, multiple windows (204) isolated from each other, the bottom of each window exposing the substrate; with epitaxial lateral overgrowth, forming an epitaxial structure (212) inside each window and a part of the mask layer around the window, respectively, each epitaxial structure having a trapezoidal cross section with a long bottom and a short top, and a gap between adjacent epitaxial structures forming a first deep trench (214); etching each epitaxial structure, forming a first shoulder (218) and a second shoulder (221) at both sides of each epitaxial structure, respectively, and forming a deep isolation trench above the mask layer between the adjacent epitaxial structures.

Abstract: A semiconductor light emitting device is provided and includes a protective element including a first lower conductivity-type semiconductor layer and a second lower conductivity-type semiconductor layer. First and second lower electrodes are connected to the first lower conductivity-type semiconductor layer and the second lower conductivity-type semiconductor layer, respectively. A light emitting structure includes a first upper conductivity-type semiconductor layer, an active layer, and a second upper conductivity-type semiconductor layer sequentially formed on the protective element. First and second upper electrodes are connected to the first upper conductivity-type semiconductor layer and the second upper conductivity-type semiconductor layer, respectively.

Abstract: In a nitride semiconductor light emitting diode including a substrate made of a nitride semiconductor, a first conductive-type nitride semiconductor layer formed on the substrate, an active layer made of a nitride semiconductor, and a second conductive-type nitride semiconductor layer, characterized in that light emitted is extracted from the under surface side of the substrate or the upper surface side of the second conductive-type nitride semiconductor layer, an intermediate layer is formed between the substrate and the active layer, and dislocations is allowed to generates from the dislocation generating layer as the origin and to distribute in a light emitting region of the active layer.

Abstract: The present invention provides methods for making pnictide compositions, particularly photoactive and/or semiconductive pnictides. In many embodiments, these compositions are in the form of thin films grown on a wide range of suitable substrates to be incorporated into a wide range of microelectronic devices, including photovoltaic devices, photodetectors, light emitting diodes, betavoltaic devices, thermoelectric devices, transistors, other optoelectronic devices, and the like. As an overview, the present invention prepares these compositions from suitable source compounds in which a vapor flux is derived from a source compound in a first processing zone, the vapor flux is treated in a second processing zone distinct from the first processing zone, and then the treated vapor flux, optionally in combination with one or more other ingredients, is used to grow pnictide films on a suitable substrate.

Abstract: Disclosed are a light emitting device, a method for manufacturing the same, a light emitting device package, and a lighting system. The light emitting device includes a first conductive semiconductor layer, an active layer comprising a well layer and a barrier layer on the first conductive layer, and a second conductive semiconductor layer on the active layer. The well layer includes a first well layer closest to the first conductive semiconductor layer and having a first energy bandgap, a third well layer closest to the second conductive semiconductor layer and having a third energy bandgap, and a second well layer interposed between the first and third well layers and having a second energy bandgap. The third energy bandgap of the third well layer is greater than the second energy bandgap of the second well layer.

Abstract: A photonic device comprises a substrate and a dielectric material including two or more openings that expose a portion of the substrate, the two or more openings each having an aspect ratio of at least 1. A bottom diode material comprising a compound semiconductor material that is lattice mismatched to the substrate occupies the two or more openings and is coalesced above the two or more openings to form the bottom diode region. The device further includes a top diode material and an active diode region between the top and bottom diode materials.

Abstract: A method for manufacturing a radiation-emitting component (1) in which a field distribution of a near field (101, 201) in a direction perpendicular to a main emission axis of the component is specified. From the field distribution of the near field, an index of refraction profile (111, 211, 511) along this direction is determined. A structure is determined for the component such that the component will have the previously determined index of refraction profile. The component is constructed according to the previously determined structure. A radiation-emitting component is also disclosed.

Abstract: According to one embodiment, a semiconductor light emitting device includes: a first semiconductor layer; a second semiconductor layer; and a light emitting layer provided between the first and the second semiconductor layers. The first semiconductor layer includes a nitride semiconductor, and is of an n-type. The second semiconductor layer includes a nitride semiconductor, and is of a p-type. The light emitting layer includes: a first well layer; a second well layer provided between the first well layer and the second semiconductor layer; a first barrier layer provided between the first and the second well layers; and a first Al containing layer contacting the second well layer between the first barrier layer and the second well layer and containing layer containing Alx1Ga1-x1N (0.1?x1?0.35).

Abstract: A light source capable of solving a problem in which the etendue is increased when random polarization is converted into a specific polarization is provided. A relief structure that functions as surface plasmon excitation means for exciting a surface plasmon by a specific polarization component in a polarization direction perpendicular to a first direction in an interface between metal layer 15 and first cover layer 14 in light from emission layer 13 incident on the interface is formed at the interface. The relief structure is periodic in a second direction. Projections 21A of the relief structure are extended along the first direction.

Abstract: System for wafer-level phosphor deposition. In an aspect, a semiconductor wafer is provided that includes a plurality of LED dies wherein at least one die includes an electrical contact, a photo-resist post covering the electrical contact, and a phosphor deposition layer covering the semiconductor wafer and surrounding the photo-resist post. In another aspect, a semiconductor wafer is provided that comprises a plurality of LED dies wherein at least one die comprises an electrical contact, a phosphor deposition layer covering the semiconductor wafer, and a cavity in the phosphor deposition layer exposing the at least one electrical contact.

Abstract: Disclosed are a light emitting device and a lighting system having the same. The light emitting device includes a first conductivity-type semiconductor layer, an interfacial layer including at least two superlattice structures adjacent to the first conductivity-type semiconductor layer, an active layer adjacent to the interfacial layer, and a second conductivity-type semiconductor layer adjacent to the active layer. The first conductivity-type semiconductor layer, interfacial layer, active layer, and second conductivity-type semiconductor layer are stacked in a same direction, the first and second semiconductor layer are of different conductivity types, an energy band gap of the superlattice structure adjacent to the active layer is smaller than an energy band gap of the superlattice structure adjacent to the first conductivity-type semiconductor layer.

Abstract: Provided are a solar cell and a method of manufacturing the same. The method includes: preparing a bottom substrate including sequentially stacked first and second portions, each of the first and second portions including a plurality of grains, wherein the maximum grain size of the second portion is less than the minimum grains size of the first portion; exposing the first portion of the bottom substrate by removing the second portion of the bottom substrate; and forming a photovoltaic conversion layer on the first portion of the bottom substrate.

Abstract: Devices incorporating a single to a few-layer MoS2 channels in combination with optimized substrate, dielectric, contact and electrode materials and configurations thereof, exhibit light emission, photoelectric effect, and superconductivity, respectively.

Abstract: Light-emitting devices are described herein.

Abstract: A light emitting device includes: one or plural light emitting elements having plural electrodes; a chip-like insulator surrounding the one or plural light emitting elements from a side surface side of the one or plural light emitting elements; and plural terminal electrodes electrically connected one-to-one with the plural electrodes, and having protrusions each protruding from a peripheral edge of the chip-like insulator.

Abstract: A light-emitting element disclosed in the present invention includes a light-emitting layer and a first layer between a first electrode and a second electrode, in which the first layer is provided between the light-emitting layer and the first electrode. The present invention is characterized by the device structure in which the first layer comprising a hole-transporting material is doped with a hole-blocking material or an organic compound having a large dipole moment. This structure allows the formation of a high performance light-emitting element with high luminous efficiency and long lifetime. The device structure of the present invention facilitates the control of the rate of the carrier transport, and thus, leads to the formation of a light-emitting element with a well-controlled carrier balance, which contributes to the excellent characteristics of the light-emitting element of the present invention.

Abstract: A light emitting diode (LED) structure including a substrate, a polymer layer, and an epitaxy layer is provided. The polymer layer is disposed on the substrate, wherein the polymer layer has a chemical formula of: wherein M represents sodium, zinc, magnesium, or potassium. The epitaxy layer is disposed on the polymer layer. The epitaxy layer is bonded to the substrate via the polymer layer.

Abstract: Bulk single crystals of AlN having a diameter greater than about 25 mm and dislocation densities of about 10,000 cm?2 or less and high-quality AlN substrates having surfaces of any desired crystallographic orientation fabricated from these bulk crystals.

Abstract: An electronic or optoelectronic device fabricated from a crystalline material in which a parameter of a bandgap characteristic of said crystalline material has been modified locally by introducing distortions on an atomic scale in the lattice structure of said crystalline material and the electronic and/or optoelectronic parameters of said device are dependent on the modification of said bandgap is exemplified by a radiation emissive optoelectronic semiconductor device which comprises a junction (10) formed from a p-type layer (11) and an n-type layer (12), both formed from indirect bandgap semiconductor material. The p-type layer (11) contains a array of dislocation loops which create a strain field to confine spatially and promote radiative recombination of the charge carriers.

Abstract: Provided is an epitaxial substrate for a semiconductor device, which has excellent schottky contact characteristics that are stable over time. The epitaxial substrate for a semiconductor device includes a base substrate, a channel layer formed of a first group III nitride containing at least Ga and having a composition of Inx1Aly1Gaz1N (x1+y1+z1=1), and a barrier layer formed of a second group III nitride containing at least In and Al and having a composition of Inx2Aly2Gaz2N (x2+y2+z2=1), wherein the barrier layer has tensile strains in an in-plane direction, and pits are formed on a surface of the barrier layer at a surface density of 5×107/cm2 or more and 1×109/cm2 or less.