Abstract: A reduced component wear valve is comprised of a valve body having a passage therethrough and a disc attached to a rotatable shaft. The disc is utilized with a seal forming a gap between the disc and the seal proximate to the rotational axis of the disc. When the disc is in the open position, the seal major axis is greater then the disc diameter and they do not touch. As the disc rotates to near closure, the disc perimeter engages the minor axis of the seal (which is smaller than the disc diameter), and the disc stretches the seal in the minor axis direction thus decreasing the major axis such that the gap is closed. The seal can be pre-formed in an elliptical shape or it can be formed into an elliptical shape by a retaining mechanism. The seal may be a single-piece or a multi-piece assembly press-fit into the valve body. Zero or light disc to seal contact during the majority of the valve disc rotation minimizes valve seal wear and rotational friction.

Abstract: A poppet valve disposed in a dispensing valve assembly includes a supporting member. The supporting member has a resilient flap. A sealing member slides over the resilient flap of the support member, so that the sealing member is not damaged or permanently deformed by the support member. Thus, the leakage is prevented when the fluid passageway is closed.

Abstract: In general, the invention relates to a ported slide gate valve having a gate for regulating the flow of a fluid through the valve, a seat located in the valve interior, and a means for causing the gate to move in such a manner that the gate fractures any scale built up in the lower portion of the valve interior, prior to the gate's movement to a valve closed position. The scale is fractured in a direction away from the seat and deposited in the fluid. More particularly, the means for causing the gate to move includes a primary piston and a secondary piston, where the primary piston is coupled to the gate. In the valve closed position, the secondary piston holds the primary piston in the desired position. A movement of the secondary piston causes the gate to move to fracture the scale in the lower portion of the valve interior.

Abstract: A valve for sampling a process from a tank or conduit includes an internal cavity in communication with at least one inlet and an outlet. A valve actuating rod includes a sealing tip attached to one end thereof. The valve actuating rod is movable to open and close the inlet to the internal cavity. Furthermore, a seal is provided to isolate the valve actuating rod and the outside environment from the process. The seal is formed on the process side of the bottom wall of the internal cavity in order to ensure that the process material, cleaning material, steam, etc. drains completely out of the internal cavity of the valve.

Abstract: A linear motion leadthrough for a rod (2) which has a first end (7), a second end (8) and an outer surface (27) and whose first end (7) projects into a vacuum area (6) of a vacuum installation while its second end (8) is located outside of the vacuum area, comprises:

Abstract: An oxygen scavenging composition or system is provided comprising an oxygen scavenging material, a photoinitiator, and at least one catalyst effective in catalyzing an oxygen scavenging reaction, wherein the photoinitiator comprises a benzophenone derivative containing at least two benzophenone moieties. A film, a multi-phase composition, a multi-layer composition, a multi-layer film, an article comprising the oxygen scavenging composition, a method for preparing the oxygen scavenging composition, and a method for scavenging oxygen are also provided. Non-extractable benzophenone derivative photoinitiators and methods for preparing same are also provided.

Abstract: The present invention features novel methods and compositions for coating textile substrates, wherein the coating compositions are composed of a coating agent selected from one of (a) an azetidinium polymer, (b) a guanidine polymer, (c) a mixture of an azetidinium polymer and a guanidine polymer, and (d) a copolymer of an azetidinium monomer and a guanidine monomer. Textile substrates coated with the compositions provide high quality printed images when printed with an ink containing a reactive dye having ionizable and/or nucleophilic groups capable of reacting with the coating agent in the textile coating composition. Images printed on a textile substrate coated with a coating composition of the invention are bleed-resistant, water-resistant (e.g., water-fast), detergent-resistant (e.g., detergent-fast), and/or are characterized by an enhanced chroma and hue.

Abstract: Compositions and methods for wrinkle reduction in fabrics, including washable clothes, dry cleanable clothes, linens, bed clothes, draperies, window curtains, shower curtains, table linens, and the like requiring little, if any, pressing, ironing, and/or steaming are disclosed.

Abstract: The present invention provides hydrofluorocarbon compositions suitable for use in a wide range of applications. The compositions of the present invention tend to be soluble in hydrocarbon lubricating oils, and thus, are especially useful in replacing CFC and HCFC compositions in refrigeration applications.

Abstract: Mono-, oligo- and polymers comprising one or more identical or different recurring units of formula I

Abstract: An aqueous composition containing a polymer or copolymer of a 3,4-dialkoxythiophene in which the two alkoxy groups may be the same or different or together represent an optionally substituted oxy-alkylene-oxy bridge, a polyanion and a non-Newtonian binder; a method for preparing a conductive layer comprising: applying the above-described aqueous composition to an optionally subbed support, a dielectric layer, a phosphor layer or an optionally transparent conductive coating; and drying the thereby applied aqueous composition; antistatic and electroconductive coatings prepared according to the above-described method for preparing a conductive layer; a printing ink or paste comprising the above-described aqueous composition; and a printing process comprising: providing the above-described printing ink; printing the printing ink on an optionally subbed support, a dielectric layer, a phosphor layer or an optionally transparent conductive coating.

Abstract: An electric resistance material comprises an Fe—Cr—Ni alloy having composition of C up to 0.1%, Si up to 5%, Mn up to 6%, 9-32% Cr, 6-25% Ni, N up to 0.2%, 0-3% Mo, 0-4% Cu, 0-5% Al, 0-0.4% Ti, 0-0.4% Nb, 0-0.005% B and the balance being substantially Fe with the previsions that the value A defined by the formula (1) and the value B defined by the formula (2) are not less than 78 and not less than 14, respectively. The electric resistance material is high of resistivity with less temperature dependency, and a resistor made therefrom works well without noises during flow of electricity. 1 A = 0.008 × ( % ⁢   ⁢ Cr ) 3 - 0.43 × ( % ⁢   ⁢ Cr ) 2 + 8.03 × ( % ⁢   ⁢ Cr ) + 6.8 × ( % ⁢   ⁢ Si ) + 10.9 × ( % ⁢   ⁢ Al ) + 0.56 × ( % ⁢   ⁢ Mo ) + 0.

Abstract: An electrically conducting composite is made by providing an aerogel structure of nonconducting material, exposing the aerogel structure to a mixture of RuO4 and a nonpolar solvent in an inert atmosphere, wherein the mixture is held initially at a first temperature that is below the temperature at which RuO4 decomposes into RuO2 in the nonpolar solvent and in the presence of the aerogel, and allowing the mixture to warm to a second temperature that is above the temperature at which RuO4 decomposes to RuO2 in the nonpolar solvent and in the presence of the aerogel, wherein the rate of warming is controlled so that as the mixture warms and the RuO4 begins to decompose into RuO2, the newly formed RuO2 is deposited throughout the aerogel structure as a three-dimensionally networked conductive deposit.

Abstract: A lifter with an adjustable wheel base comprising a lever assembly, an adjustable axle assembly, and a lifting assembly. The lifting assembly may be magnetic and may additionally comprise safety cables having other attachment means.

Abstract: A braking device includes a brake wheel, a pair of rotation shafts, a pair of brake arms which is rotatably supported through the rotation shafts, a pair of brake pads arranged at one end of the brake arms and contacting and separating from the brake wheel, and a brake part connected to another end of the brake arms for providing and releasing a braking force of the brake pads. When the centers of the rotation shafts are fulcrums, the centers of contact of the brake pads with the brake wheel are points of action, and the connections between the brake arms and the brake part are power points, the fulcrums, the points of action, and the power points are located in a semicircular area of the brake wheel.

Abstract: A fence system tensioning apparatus for tensioning a section of fencing material extending between support fence posts. The tensioner is rotatable with a rotation tool such as a wrench without contacting the outer side walls of a generally cylindrical sleeve member. The sleeve may be rotated 360° about its rotational axis. A fencing material connection member on the sleeve receives and retains fencing material as the sleeve is rotated by turning rotational members and the material tensioned. A lock nut assembly is attached to the sleeve to prevent rotation of the sleeve after the material has been properly tensioned.

Abstract: An apparatus comprising control circuitry formed on a substrate, and a plurality of active media coupled to the control circuitry and formed in a plurality of planes over the substrate. A method comprising forming a pair of junction regions on a substrate separated by a channel length; and forming a channel material overlying and coupled to the pair of junction regions having a dimension at least equal to the channel length. An apparatus comprising a contact formed in a first plane over a device structure; and a device coupled to the contact and formed in a second plane a greater distance from the substrate than the first plane.

Abstract: The present invention relates to a semiconductor device (1) with one or more current confinement regions (20) and to a method of manufacturing such a device, particularly buried heterostructure light emitting devices such as semiconductor lasers and light emitting diodes. The device comprising a doped semiconductor substrate (2) of a first conduction type, a buried heterojunction active layer (10) above the substrate (2), a current conduction region (4) above the active layer (10), one or more current confinement regions (20) formed over the substrate (2) adjacent the active layer (10), the current conduction region (4) and current confinement region (20) being arranged in use to channel electric current to the active layer (10).

Abstract: An encapsulation for an organic light emitting diode (OLED) device is disclosed. The encapsulation includes a sealing dam surrounding the cell region of the OLED device to support a cap. Spacer particles are randomly located in the cell region to prevent the cap from contacting the active components, thereby protecting them from damage. The sealing dam provides a sealing region between the edge of the cap and dam in which an adhesive is applied to seal the OLED device. The use of the sealing dam advantageously enables devices to be formed with narrower sealing widths.

Abstract: A light emitting device capable of reducing degradation caused by dispersion of impurities such as moisture, oxygen, an alkaline metal, and an alkaline earth metal is provided. Specifically, a flexible light emitting device with an OLED formed on a plastic substrate is provided. In a light emitting device using a substrate, a circular polarizing plate has a single layer or two or more layers of barrier films formed of a compound or compounds selected from AlNXOY, AlXNY, and Al2O3, which is (are) capable of preventing oxygen and moisture from seeping into an organic light emitting layer of an OLED as well as preventing an alkaline metal, an alkaline earth metal, and other impurities from penetrating an active layer of a TFT.

Abstract: A light emitting device and a manufacturing method thereof and a display used the light emitting device, in which fine patterning for the light emitting device is realized by a simple process and the light leakage is prevented and the efficiency at extracting light is increased, are provided. The light emitting device provides an organic electroluminescent (EL) device in which electrodes and a luminescent layer are formed, a diffraction grating or a zone plate, and a filter. Light emitted from the luminescent layer transmits through the diffraction grating or the zone plate, which is formed with a designated grating pitch, or is reflected at the diffraction grating or the zone plate. With this, the transmitting or reflecting light is controlled to be in a designated angle region. And when the light is transmitted through the filter, light having different color tone and chromaticity from those of the light emitted from the luminescent layer is extracted.

Abstract: A semiconductor wafer includes a plurality of chip areas having circuit elements, a scribe line area for defining the chip areas, and a plurality of test element group (TEG) modules. The TEG modules are group formed on the scribe line area. Each of the TEG modules has test transistors, a common source pad, and a common body pad. A global gate pad is commonly connected to gates of test transistors in the test element group modules. Global drain pads are shared by respective test transistors in the TEG modules. In other words, each drain pad is commonly connected to corresponding drains of test transistor in at least two TEG modules such that a drain pad is shared by plural TEG modules, considerably reducing an area occupied by each TEG module.

Abstract: An insulating film 103 for making an under insulating layer 104 is formed on a quartz or semiconductor substrate 100. Recesses 105a to 105d corresponding to recesses 101a to 101d of the substrate 100 are formed on the surface of the insulating film 103. The surface of this insulating film 103 is flattened to form the under insulating layer 104. By this flattening process, the distance L1, L2, . . . , Ln between the recesses 106a, 106b, 106d of the under insulating layer 104 is made 0.3 &mgr;m or more, and the depth of the respective recesses is made 10 nm or less. The root-mean-square surface roughness of the surface of the under insulating film 104 is made 0.3 nm or less. By this, in the recesses 106a, 106b, 106d, it can be avoided to block crystal growth of the semiconductor thin film, and crystal grain boundaries can be substantially disappeared.

Abstract: An electro-luminescent display and a method of manufacturing thereof prevents the formation of a barrier interface between the anode electrode and the electro-luminescent layer by placing the electro-luminescent layer directly on the anode electrode so that there is no need to etch a subsidiary layer so that the electro-luminescent layer and the anode electrode have excellent electrical contact. The elimination of this etching step prevents damage to the anode electrode caused by collision of ions with the anode electrode during the etching process. Further, etch remainders or contaminant particles that exist in the etchant gas are prevented from accumulating on the anode electrode. Thus, the charge carriers of the anode are easily transported across the interface between the anode electrode and the electro-luminescent layer so as to greatly improve the expected life span, the brightness, and the efficiency of the electro-luminescent display.

Abstract: A display device capable of obtaining a constant luminance without being influenced by temperature change is provided as well as a method of driving the display device. A current mirror circuit composed of a first transistor and a second transistor is provided in each pixel. The first transistor and second transistor of the current mirror circuit are connected such that their drain currents are kept almost equal irrespective of the level of load resistance. By controlling the OLED drive current using the current mirror circuit, a change in OLED drive current due to fluctuation in characteristics between transistors is avoided and a constant luminance is obtained without being influenced by temperature change.

Abstract: New Group III based diodes are disclosed having a low on state voltage (Vf, and structures to keep reverse current (Irev) relatively low. One embodiment of the invention is Schottky barrier diode made from the GaN material system in which the Fermi level (or surface potential) of is not pinned. The barrier potential at the metal-to-semiconductor junction varies depending on the type of metal used and using particular metals lowers the diode's Schottky barrier potential and results in a Vf in the range of 0.1-0.3V. In another embodiment a trench structure is formed on the Schottky diodes semiconductor material to reduce reverse leakage current. and comprises a number of parallel, equally spaced trenches with mesa regions between adjacent trenches. A third embodiment of the invention provides a GaN tunnel diode with a low Vf resulting from the tunneling of electrons through the barrier potential, instead of over it. This embodiment can also have a trench structure to reduce reverse leakage current.

Abstract: Substrates having increased thermal conductivity are provided, comprising a body having opposed surfaces and a cavity that opens on at least one surface, the cavity containing at least one material having a greater thermal conductivity than the body. Devices are provided comprising a substrate and a semiconductor over a surface of the substrate. Methods of forming devices according to the invention are also provided.

Abstract: An improved barrier stack for sealing devices is described. The barrier stack includes at least first and second base layers bonded together with a high barrier adhesive. A base layer includes a flexible support coated on at least one major surface with a barrier layer. The adhesive advantageously seals defects, such as pinholes in the barrier layer, thus improving the barrier properties.

Abstract: A semiconductor laser device includes an active layer configured to radiate light, a light reflecting facet positioned on a first side of the active layer, and a light emitting facet positioned on a second side of the active layer thereby forming a resonator between the light reflecting facet and the light emitting facet. A diffraction grating is positioned within the resonator along a portion of the length of the active layer and the laser device is configured to operate as a multiple mode oscillation device. A window structure is provided between an end of the active layer and one of the light reflecting and light emitting facets, and the window structure is configured to reduce a reflectivity of the one of the light reflecting and light emitting facets.

Abstract: Irregularities are formed on at least a side surface of a light emitting layer of a light emitting element. In one form of the invention, an n-type layer which is a Group-III nitride compound semiconductor or the like, a light emitting layer, and a p-type layer are successively formed on a sapphire substrate through MOVPE or the like. Then, dry etching is carried out to expose the n-type layer to form a pedestal electrode. In this etching process, an etching pattern is employed to form a wave shape on the periphery of the p-type layer.

Abstract: Efficiency of leading out light released from an active layer, i.e. the external quantum efficiency, can be improved remarkably by processing a light lead-out surface to have an embossment. A layer containing a p-type dopant like magnesium (Mg) is deposited near the surface of a p-type GaN layer to diffuse it there, and a p-side electrode is made on the p-type GaN layer after removing the deposited layer. This results in ensuring ohmic contact with the p-side electrode, preventing exfoliation of the electrode and improving the reliability.

Abstract: There is disclosed a semiconductor light emitting element formed by selective growth and being high in light emitting efficiency, in which at least one GaN-based layer grown by ELO is stacked/formed on a sapphire substrate, and a fluorescent substance for converting an ultraviolet light to a visible light is contained in a selective growth mask material layer for use in this case. Since this fluorescent substance converts the ultraviolet light to the visible light, a binding efficiency of the ultraviolet light to the fluorescent substance is enhanced in either one of a center light emitting type and UV light emitting type of light emitting elements. By further containing the fluorescent substance into a passivation film, the efficiency is further enhanced.

Abstract: A color filter substrate for a liquid crystal display device includes a polarizing substrate, a black matrix positioned on the polarizing substrate, a color filter layer positioned on the black matrix, and a common electrode positioned on the color filter layer.

Abstract: Disclosed is a technique for increasing the shelf life of devices, such as OLED which requires hermetic sealing from moisture and oxygen with out increasing the bonding width. In one embodiment, the permeation path of moisture or oxygen is increased without increasing the bonding width. This is achieved by using a grooved interface between the cap and substrate on which the components of the device are formed. The grooved interface can comprise various geometric shapes.

Abstract: A gallium nitride compound semiconductor light emitting element has a nitride layered body formed on a translucent substrate. A P type pad electrode, an N type pad electrode and a P type electrode are formed at the layered body, each having the desired reflectance. The thickness of the translucent substrate and the nitride layered body stacked thereon of the semiconductor light emitting element is 60 &mgr;m to 460 &mgr;m.

Abstract: A turn-off high power semiconductor device with the inner pnpn-layer structure of a Gate-Commutated Thyristor and a first gate on the cathode side has an additional second gate on the anode side, said second gate contacting the n-doped base layer and having a second gate contact. A second gate lead which is of rotationally symmetrical design and is disposed concentrically with respect to the anode contact is in contact with said second gate contact. Said second gate lead is brought out of the component and electrically insulated from the anode contact.

Abstract: The invention relates to new mono-, oligo- and poly-difluorovinyl(hetero)arylenes comprising one or more identical or different recurring units of formula I 1

Abstract: In a semiconductor multi-layer structure in which a first SiGe layer having a first conductivity-type and high impurity concentration, a second SiGe layer having the first conductivity-type and a low impurity concentration and a Si layer having a low impurity concentration are formed one on another in this order on a Si substrate of the first conductivity-type, a channel is formed in a part of the Si layer and a source electrode passes through the second SiGe layer of low impurity concentration to electrically contact the first SiGe layer of high impurity concentration or the substrate.

Abstract: A semiconductor device with improved heat radiation characteristics that is formed by employing a lattice-mismatched system semiconductor thin-film crystal layered product. In fabricating an HBT on a semi-insulating GaAs substrate, the HBT comprised of a material system lattice-matched to InP that is different from the substrate in the lattice constant, a structure is employed that comprises alloy compound semiconductor layers with thermal resistivities that increase with increasing lattice constant (e.g., InxGa1−xAs) and alloy compound semiconductor layers with thermal resistivities that decrease with increasing lattice constant (e.g., InyGa1−yP) as a lattice-strain-relaxed buffer layer. By using the above-mentioned lattice-strain-relaxed buffer layer, the thermal resistivity of the buffer layer can be reduced compared to a lattice-strain-relaxed buffer layer consisting of only InxGa1−xAs materials and a lattice-strain-relaxed buffer layer consisting of only InyGa1−yP materials.

Abstract: A method of forming a lateral bipolar transistor without added mask in CMOS flow including a p-substrate; patterning and n-well implants; pattern and implant pocket implants for core nMOS and MOS; pattern and implants pocket implants I/O nMOS and pMOS; sidewall deposit and etch and then source/drain pattern and implant for nMOS and pMOS. The method includes the steps of forming emitter and collector contacts by implants used in source/drain regions; forming an emitter that includes implants done in core pMOS during core pMOS LDD extender and pocket implant steps and while the collector omits the core pMOS LDD extender and pocket implants; forming a base region below the emitter and collector contacts by the n-well region with said base region going laterally from emitter to collector being the n-well and including pocket implants; and forming base contact by said n-well region and by implants used in nMOS source/drain regions.

Abstract: A silicon-on-insulator (SOI) gated diode and non-gated junction diode are provided. The SOI gated diode has a PN junction at the middle region under the gate, and which has more junction area than a normal diode. The SOI non-gated junction diode has a PN junction at the middle region thereof, and then also has more junction area than a normal diode. The SOI diodes of the present invention improve the protection level offered for electrical overstress (EOS)/electrostatic discharge (ESD) due to the low power density and heating for providing more junction area than normal ones. The I/O ESD protection circuits, which comprise primary diodes, a first plurality of diodes, and a second plurality of diodes, all of which are formed of the present SOI diodes, could effectively discharge the current when there is an ESD event. And, the ESD protection circuits, which comprise more primary diodes, could effectively reduce the parasitic input capacitance, so that they can be used in the RF circuits or HF circuits.

Abstract: A packaged semiconductor chip includes features such as a chip carrier having a large thermal conductor which can be solder-bonded to a circuit board so as to provide enhanced thermal conductivity to the circuit board and electromagnetic shielding and a conductive enclosure which partially or completely surrounds the packaged chip to provide additional heat dissipation and shielding. The packaged unit may include both an active semiconductor chip and a passive element, desirably in the form of a chip, which includes resistors and capacitors. Inductors may be provided in whole or in part on the chip carrier. A module includes two circuits and an enclosure with a medial wall between the circuits to provide electromagnetic shielding between the circuits.

Abstract: In a substrate, a portion for forming wiring extending to a connection terminal is provided with a recess. The connection terminal and the wiring are covered by an interlayer insulating film, and an opening is provided in a portion corresponding to the connection terminal. Thereby, a difference in level between the connection terminal and the wiring extending thereto is reduced.

Abstract: A semiconductor device having: a substrate having a first area and a second area surrounding the first area; an insulating film formed in the second area; electrodes formed above the surface of the substrate in the first area; dielectric films formed above the electrodes; and an opposing electrode formed above the dielectric films, wherein the shape of a side wall of the insulating film includes a shape reflecting the outer peripheral shape of a side wall of the electrode facing the side wall of the insulating film. The semiconductor device of high integration, low cost and high reliability can be realized.

Abstract: An electro-optical device includes a pair of substrates including a first substrate and a second substrate, an electro-optical material sandwiched between the pair of substrates, a shading film having a predetermined pattern which is at least partially embedded in the first substrate at the surface facing the electro-optical material, display electrodes which are placed on the second substrate at the surface facing the electro-optical material, and lines connected to the display electrodes directly or through switching elements. In accordance with the electro-optical device having such a shading film, it is possible to reduce or prevent coating defects in an alignment layer, nonuniform rubbing treatment to the alignment layer, and cracking of a counter electrode due to the steps in the upper layers resulting from the formation of the shading film.

Abstract: By controlling the luminance of light emitting element not by means of a voltage to be impressed to the TFT but by means of controlling a current that flows to the TFT in a signal line drive circuit, the current that flows to the light emitting element is held to a desired value without depending on the characteristics of the TFT. Further, a voltage of inverted bias is impressed to the light emitting element every predetermined period. Since a multiplier effect is given by the two configurations described above, it is possible to prevent the luminance from deteriorating due to a deterioration of the organic luminescent layer, and further, it is possible to maintain the current that flows to the light emitting element to a desired value without depending on the characteristics of the TFT.

Abstract: In a TFT with a GOLD structure, there is provided a structure which is able to improve an operating characteristic and reliability and reduce an off current value in order to reduce power consumption of a semiconductor device. The surface of LDD region (4) overlapped with a portion (7a) of a gate electrode through a gate insulating film (6) interposed therebetween is extremely flattened. Thus, it is possible to obtain a TFT structure which is capable of reducing a parasitic capacitance in the LDD region of the TFT with the GOLD structure, reducing an off current value, improving reliability, and enabling high speed operation.

Abstract: So that semiconductor memory devices can be used optimally with regard to different possible operating frequencies, according to the invention, a register area is formed in which frequency information with regard to a present operating frequency can be stored in coded form and be retrieved for a configuration and adaptation of the semiconductor memory device.

Abstract: A lateral, high-voltage, FET having a low on-resistance and a buried conduction layer comprises a P-type buried layer region within an N-well formed in a P-type substrate. The P-type buried layer region is connected to a drain electrode by a first P-type drain diffusion region that is disposed in the N-well region. The P-type buried layer region is also connected to a second P-type drain diffusion region that extends down from the surface at one end of the PMOS gate region. A P-type source diffusion region, which connects to the source electrode, defines the other end of the gate region.

Abstract: An active cell for a photosensitive sensor that includes photosensitive diode in which the transistors of the cell are implemented using CMOS technology. The cell operates with an exposure phase in which the quantity of light impinging on the cell is detected followed by a scanning phase during which the luminance information caused by the impinging light is extracted from the cell. The cell is arranged in such a way to virtually completely isolate the charge accumulation node from the remainder of the cell after the exposure phase to eliminate stray accumulation of charge carriers.