271 results about "Acceptor" patented technology

The invention relates to the technical field of luminescent materials, and discloses an aggregation-induced emission material, nanoparticles as well as a preparation method and application thereof, the structural general formula of the aggregation-induced emission material is as follows: # imgabs0 #, R is selected from one of the following structures: # imgabs1 # aggregation-induced emission material takes a pyridine group as an acceptor unit, and the acceptor unit is selected from one of the following structures: 1 # imgabs2 # aggregation-induced emission material; a carbon-carbon double bond and a thiophene unit are used as pi bridges, and diphenylamine, bis (4-ethylphenyl) amine and bis (4-(tert-butyl) phenyl) amine are used as strong electron donors. The donors not only provide strong electron supply ability, but also become efficient rotors due to highly twisted molecular conformation, and endow the aggregation-induced emission material with long emission wavelength and aggregation-induced emission activity.

The invention relates to a GaN-based light emitting diode epitaxial structure with high hole injection efficiency and a preparation method thereof. The epitaxial structure sequentially comprises a first semiconductor layer, an active layer, a low-temperature P-type layer and a second semiconductor layer which are arranged on the substrate, and the low-temperature P-type layer is arranged between the active layer and the P-type GaN and sequentially comprises a hole expansion layer, a hole storage layer and a hole layer. The hole expansion layer is composed of a periodic structure formed by AlN layers and low-doped Mg-GaN layers alternately. The hole storage layer is of a periodic structure composed of a GaN layer, an InGaN layer and a low-doped Mg-AlGaN layer. The hole layer is of a periodic structure of a P-type AlInGaN layer and an MgN layer and is formed in an Mg source pulse deposition mode. According to the structure, the multi-cycle heterogeneous layer design is combined with doping regulation and deposition process optimization, the Mg acceptor activation rate and the hole injection efficiency are improved, the defect density and the electron leakage are reduced, and the structure is suitable for being applied to a small-current Micro LED.

The invention belongs to the technical field of luminescence and display, and particularly relates to a D-A type green light TADF material and application thereof in OLEDs. The luminescent material comprises an oxygen bridge triphenylboron acceptor unit and oxygen bridge triphenylamine which are used as donor units, and a green light TADF material is constructed through simple coupling. The rigid large plane structure of the material limits rotation of a benzene ring, vibration relaxation of a condensed ring structure is reduced, and the photoluminescence efficiency as high as 90% is obtained. Research results show that the maximum emission peak of the device is 518 nm and the maximum external quantum efficiency (EQE) of the device is 37.8% under different doping concentrations when the OLEDs are processed by the solution, especially under the doping concentration of 5-100%, the electrogenerated emission peak change of the device is small, the EQE of 30% or above is kept, the excellent concentration quenching inhibition performance is shown, and the application prospect is attractive.

According to the deep ultraviolet laser epitaxial structure and the epitaxial growth method thereof provided by the invention, the Al component of the first waveguide layer is linearly and progressively increased from the side close to the electron injection layer to the side close to the quantum well active layer; or the Al component of the second waveguide layer is linearly and progressively decreased from the side close to the quantum well active layer to the side close to the hole injection layer to form refractive index distribution which takes the barrier layer of the quantum well active layer as the highest refractive index point and gradually decreases towards one side (the n-type side or the p-type side), so that the light field is firmly bound near the quantum well active layer, and the light limiting capability is remarkably enhanced; meanwhile, high-low Al components of the p-type side (the second waveguide layer) gradually change to generate a strong polarization electric field, ionization of a p-type doped acceptor (such as Mg) can be promoted, two-dimensional hole gas (2DHG) can be induced, and the hole concentration is improved; the low-high Al components of the n-type side (the first waveguide layer) are gradually changed, so that two-dimensional electron gas can be induced, and the electron concentration is improved.

A method for producing a substrate comprising a buried oxide layer (1, 10, 20) or a buried nitride layer for the production of electronic components, comprising at least one step for depositing an oxide layer (1, 10, 20) or a nitride layer on a donor substrate (2, 11, 21) and / or an acceptor substrate, and a step for establishing contact between the donor substrate and the acceptor substrate (9, 14, 22), further comprising at least: a first heat treatment of the oxide layer (1, 10, 20) or the nitride layer deposited on the donor substrate (2, 11, 21) and / or the acceptor substrate (9, 14, 22) before connecting the donor substrate (2, 11, 21) with the Acceptor substrate (9, 14, 22) and a second heat treatment of the substrate, which consists of the acceptor substrate (9, 14, 22), the oxide layer (1, 10, 20) or the nitride layer and the entire donor substrate (2, 11, 21) or a part thereof, at a temperature,which is the same as or higher than the temperature applied in the first heat treatment, wherein the second heat treatment is a compression heat treatment, wherein the first heat treatment consists of applying a temperature of 600 to 1000 °C for a period of a few minutes to a few hours in a non-oxidizing inert gas or a mixture of inert gases.

The invention discloses a compound and a preparation method thereof and an electronic device, the molecular structure general formula of the compound is shown in the specification, R is selected from one of the following structures, X1-X2 are respectively and independently selected from one of oxygen atoms, sulfur atoms, selenium atoms and nitrogen atoms, and X is a positive integer. X < 3 > to X < 4 > are respectively and independently selected from one of the following structures; and X < 5 > to X < 6 > are respectively and independently selected from any one of alkyl groups. According to the compound provided by the invention, the electron pushing and pulling capability in the compound is adjusted by changing the structures of a donor and an acceptor, so that the purpose of regulating and controlling molecular electron cloud distribution and energy level is achieved, and key physical properties such as emission wavelength, radiative transition rate (kr) and backlash crossing rate (kRISC) of a material are systematically regulated and controlled. The compound as a guest material of a luminescent layer has good comprehensive performance when being applied to organic electroluminescent devices for solution processing and vacuum evaporation.

The application provides a thin film with an epsilon phase gallium oxide hetero-epitaxial structure and a preparation method thereof, which comprises, from bottom to top, a substrate layer, a first gallium oxide layer and a second gallium oxide layer; the first gallium oxide layer is an epsilon phase gallium oxide layer doped with magnesium Mg, and the magnesium Mg doping acts as an acceptor type trap in the epsilon phase gallium oxide, effectively compensates for the donor type defects of the epsilon phase gallium oxide, and improves the overall resistivity of the epsilon phase gallium oxide thin film. The preparation method adopts a metal organic chemical vapor deposition method, and the growth temperature of the second gallium oxide layer is higher than that of the first gallium oxide layer; and the molar flow ratio of the magnesium source to the gallium source is controlled to be 0.0001-0.1 during preparation. The application introduces appropriate Mg doping through a nucleation layer stage, so that the Mg acts as an acceptor type trap to compensate for donor type defects, while improving the crystal nucleation quality, reducing dislocations and leakage channels, and realizing the dual optimization of the crystal quality and electrical performance of the epsilon phase gallium oxide thin film, thereby effectively reducing the thin film leakage current and improving the resistivity.

This invention provides an organic ferroelectric eutectic material, its preparation method, and its applications, relating to the field of ferroelectric materials technology. The organic ferroelectric eutectic material constructs a crystal system with "rigid constraint and flexible adaptation coexisting, dipole order and controllable polarization synchronously" through "molecular selection-supramolecular assembly-crystal structure regulation," achieving a synergistic effect of high Curie temperature, strong polarization characteristics, and excellent flexibility. The preparation method of the organic ferroelectric eutectic material utilizes a simplified "solvent dissolution-solvent evaporation" process, leveraging the mediating effect of the solvent to promote the supramolecular self-assembly of donor and acceptor molecules. This achieves the preparation of an organic ferroelectric eutectic material possessing both high Curie temperature, strong polarization characteristics, and excellent flexibility. The preparation method has multiple advantages, including "stable process, low cost, and suitability for large-area processing," making it a simple, efficient, and universally applicable preparation method suitable for large-scale industrial production.

The invention relates to a method for producing a perovskite-type single crystal, and a perovskite-type single crystal. Provided are: a single crystal which exhibits a high electromechanical coupling coefficient and a high coercive field when used in a piezoelectric element; and a method for producing the single crystal. The method is a method for producing a perovskite-type single crystal, in which a first single crystal of a perovskite type is prepared by firing a raw material containing an acceptor in an air atmosphere, a step (2) including firing the first single crystal in a reducing atmosphere, and a step (3) including firing the single crystal prepared in step (2) in an air atmosphere, in this order, a perovskite-type single crystal having a higher coercive field value than a first single crystal is prepared.

The embodiment of the invention discloses a donor-receptor complementary co-doped hafnium oxide-based ferroelectric film material and a preparation method thereof. The method comprises the following steps: according to the composition of the donor-receptor complementary co-doped hafnium oxide-based ceramic target material, mixing raw material powder to obtain mixed raw material powder; calcining the mixed raw material powder under a preset condition; pressing and molding the calcined product into a target material green body; and sintering the target material green body to obtain the donor-receptor complementary co-doped hafnium oxide-based ceramic target material. Wherein the composition of the donor-acceptor complementary co-doped hafnium oxide-based ceramic target material is expressed as AxByHf (1-x-y) O2, A is a donor and comprises elements niobium and tan, and B is an acceptor and comprises elements yttrium and lanthanum; x is more than 0.01 and less than 0.05, and y is more than 0.01 and less than 0.05; the raw material powder containing the donor comprises niobium oxide and tantalum oxide, and the raw material powder containing the acceptor comprises yttrium oxide and lanthanum oxide; and taking the donor-acceptor complementary co-doped hafnium oxide-based ceramic target material as a sputtering target, and obtaining the donor-acceptor complementary co-doped hafnium oxide-based ferroelectric material film by using a pulse laser deposition method.

The embodiment of the invention provides a SiC LDMOS device, a manufacturing method and a chip. The SiC LDMOS device comprises a P-type substrate; the N-type buried layer is located in the P-type substrate; the N-type epitaxial layer is located on the surface of the P-type substrate and the surface of the N-type buried layer; the P-type injection layer is located in the N-type epitaxial layer, and the bottom of the P-type injection layer is connected with part of the surface of the N-type buried layer; the P-type body region is located in the N-type epitaxial layer and extends into the P-type substrate; and the N-type buffer layer is located in the P-type injection layer and extends into the N-type buried layer. When the device is in a reverse withstand voltage state, the drift region is depleted, ionization donors in the P-type injection layer and the P-type substrate emit power lines and point to ionization acceptors of the N-type buried layer and the N-type epitaxial layer, the N-type epitaxial layer and the N-type buried layer are mutually overlapped, electric field distribution in the drift region of the device can be effectively adjusted, an electric field peak is introduced to the surface of the drift region of the device, and the device is prevented from being damaged. And the overall electric field of the drift region is lifted, so that the voltage resistance of the device is improved.

To reduce an on-resistance while maintaining a gate-drain breakdown voltage, in a bidirectional switch.SOLUTION: A nitride semiconductor device 10 includes a bidirectional switch 12. The bidirectional switch 12 includes a semiconductor substrate 40, a first nitride semiconductor layer 42, a second nitride semiconductor layer 44 having a bandgap larger than that of the first nitride semiconductor layer 42, a first drain electrode 28 and a second drain electrode 30 which contact the second nitride semiconductor layer 44, a third nitride semiconductor layer 50 containing acceptor-type impurities, and a gate electrode 26 located above the third nitride semiconductor layer 50. The third nitride semiconductor layer 50 includes a ridge part 54 contacting the gate electrode 26 and an extension part 56 thinner than the ridge part 54. The extension part 56 includes a first extension region 56A extending from the ridge part 54 toward the first drain electrode 28, and a second extension region 56b extending from the ridge part 54 toward the second drain electrode 30.SELECTED DRAWING: Figure 5

The present application relates to ferroelectric nematic liquid crystal (FNLC) compounds characterized by chemical structures having electron donor–acceptor chromophores connected via linkers. The compounds have a general structure of A1–L1–A2–L2–(Ax–Ly)n–B, where A and B are aryl or heteroaryl groups, and L are linkers selected to promote spontaneous polar alignment in the nematic phase. The FNLCs enable enhanced second-order nonlinear optical properties and electro-optic coefficients (r33), with values exceeding, e.g., 30 pm / V in some embodiments. The FNLC compounds also exhibit absorption maxima above 400 nm, indicating extended π-conjugation and strong intramolecular charge transfer. The present application also includes compositions and mixtures of such compounds, which may form glassy ferroelectric nematic phases suitable for integration into nonlinear optical devices.

The invention relates to a laser-assisted heterogeneous bonding stripping method, a heterogeneous bonding structure and an optical element, and the method comprises the following steps: preparing an acceptor substrate and a donor substrate which is provided with a first surface and a second surface which are opposite to each other; bonding the to-be-bonded surface of the receptor substrate with the second surface; focusing laser on a preset stripping surface in the donor substrate from the first surface, and performing laser scanning so as to sequentially form a plurality of modified points on the preset stripping surface; after the laser scanning is completed, stripping the donor substrate along the preset stripping surface to obtain a heterogeneous bonding structure comprising an acceptor substrate and a donor film bonded on the acceptor substrate, and the residual donor substrate; the heterogeneous bonding structure is prepared by the laser-assisted heterogeneous bonding stripping method. The optical element comprises the heterogeneous bonding structure. The method provided by the invention has the effect of realizing high-efficiency, high-quality and low-cost manufacturing of a normal-temperature, high-efficiency and lossless heterogeneous bonding structure.

The invention relates to an asymmetric small organic molecule photovoltaic acceptor material based on an iodo-thiophene central core as well as a preparation method and application of the asymmetric small organic molecule photovoltaic acceptor material based on the iodo-thiophene central core, and creatively designs the asymmetric small organic molecule photovoltaic acceptor material based on the iodo-thiophene central core. On the basis of keeping the efficient photoelectric property, the asymmetric iodo-thiophene central core is introduced, so that the fine regulation and control on the molecular stacking behavior and the thin film morphology are realized. The asymmetric small organic molecule photovoltaic acceptor material has good solubility in various organic solvents, molecular accumulation can be finely regulated and controlled through asymmetric central core design, intermolecular pi-pi interaction and accumulation of end groups are enhanced, more orderly-arranged and optimized charge transfer channels are formed, and the asymmetric small organic molecule photovoltaic acceptor material has a good application prospect. Therefore, the crystallinity and morphology of the film are improved.

The invention belongs to the technical field of eutectic semiconductor materials, and discloses a D-A type acene-perylene bisimide eutectic crystal, an organic field effect transistor and a preparation method and application of the D-A type acene-perylene bisimide eutectic crystal and the organic field effect transistor. As a bipolar semiconductor material, the D-A acene-perylene bisimide eutectic crystal shows balanced bipolar with excellent performance, has an ultrahigh on-off ratio, and shows great application value in the aspect of electronic circuits.

The invention discloses an organic small molecular luminescent material based on a thiothiazolyl benzophenone derivative as well as preparation and application of the organic small molecular luminescent material. Thio-thiazolyl benzophenone is used as an acceptor core unit, and the molecular weight, charge transfer degree, light-emitting wavelength and other material characteristics of the material can be effectively adjusted by changing the conjugate length of the acceptor core unit and the type and size of a connecting unit. The bipolar photoelectric material connected with the donor and the acceptor can form a large torsion angle between the donor and the acceptor, so that the non-planarity of the structure is improved, the accumulation degree of the material is reduced, aggregation quenching of the material is effectively inhibited, and the problem that carriers of the unipolar organic photoelectric material are unbalanced is solved; meanwhile, the conjugate length of molecules can be effectively controlled, and the horizontal molecular orientation is improved, so that the device structure is simplified, and the device performance is improved.

A light-emitting element that can emit high brightness even at low driving voltages and has a long lifespan. One of the objectives is to provide [this]. [Solution] The light-emitting element has n (where n is a natural number of 2 or more) layers of EL between the anode and the cathode. Between the m-th (m is a natural number, 1 ≤ m ≤ n-1)th EL layer and the m+1th EL layer from the anode This comprises a first layer containing a first donor material in contact with the mth EL layer, and an electric layer in contact with the first layer. A second layer containing a subtransporting substance and a second donor substance, and the second layer and the m+1th EL It comprises a third layer containing a hole-transporting material and an acceptor material in contact with the layer.

To provide a single crystal having a large electromechanical coupling coefficient and a large coercive electric field when used as a piezoelectric element, and a method for manufacturing the same.SOLUTION: A method for manufacturing a perovskite-type single crystal, the method comprising the steps of (1) firing a raw material containing an acceptor in an air atmosphere to obtain a first perovskite-type single crystal, (2) firing the first single crystal in a reducing atmosphere, and (3) firing the single crystal obtained in step (2) in an air atmosphere, thereby obtaining a perovskite-type single crystal having a higher coercive electric field value than the first single crystal.SELECTED DRAWING: Figure 1

An organic electroluminescence device containing a cathode, an anode, and an organic layer disposed between the cathode and the anode, wherein the organic layer contains an emitting layer, a first layer, and a second layer, the first layer is disposed between the anode and the emitting layer, the second layer is disposed between the anode and the first layer, the first layer contains a first hole-transporting material and a second hole-transporting material, and the second layer contains an acceptor material having an affinity value in the range of 3.8 to 6.0 eV and at least one hole-transporting material.

The present disclosure is directed, in general, to (1) nonlinear optical (NLO) chromophores, including (2) compositions / materials / resistive layers comprising NLO chromophores, and the methods of making the compositions / materials / resistive layers comprising NLO chromophores (e.g., methods of poling and / or drying, and the like), (3) uses of NLO chromophores in electro-optic devices (e.g., electro-optic modulators (EOMs)). NLO chromophores disclosed herein not only have large EO effect, but also have fast modulation speed. In addition, NLO chromophores disclosed herein have superior refractive index, photostability and thermal stability compared to other EO Materials. As a consequence, NLO chromophores herein are particularly suited for use as EO materials in connection with low power and small footprint devices, including devices used in data acquisition systems, analog I / O modules, field transmitters, lab and field instrumentation, servo drive control modules, direct current (DC) power supply, alternating current (AC), and / or electronic load.

The invention relates to an optoelectronic component (100) comprising a first electrode (2), a second electrode (9) and a stack (20) arranged between the first electrode (2) and the second electrode (9), the stack (20) comprising at least a first light-sensitive layer (4) and a second light-sensitive layer (7), the first light-sensitive layer (4) comprising at least one perovskite absorber material having a wide band gap, and the second light-sensitive layer (7) comprising at least one perovskite absorber material having a wide band gap. And the second light-sensitive layer (7) is an organic light-sensitive layer having a narrow band gap comprising at least one donor and at least one acceptor as an organic absorbent material forming a donor / acceptor heterojunction, where the at least one donor of the second light-sensitive layer is an A-D-A compound and / or a BODIPY compound.

The application discloses a high-performance bismuth-free ZnO-Cr2O3-based pressure-sensitive ceramic and a preparation method and application of defect regulation, and belongs to the technical field of pressure-sensitive materials. The method comprises the following steps: ZnO, doped oxides, polyvinyl alcohol aqueous solution, tributyl phosphate and deionized water are ball-mixed to obtain mixed powder; after drying, sieving, granulating and compression molding, oxide-doped ZnO green bodies are obtained; after glue removal and sintering, high-performance bismuth-free ZnO-Cr2O3-based pressure-sensitive ceramic is obtained. The bismuth-free ZnO-Cr2O3-based pressure-sensitive ceramic is obtained by adopting a solid-phase sintering method, taking ZnO as main raw material, and doping multiple oxides for compression and sintering. Immovable acceptor defects and stable double Schottky barrier structures are formed in the oxides enriched at the ZnO grain boundaries, which provides an important technical thought for the electrical performance optimization of different system pressure-sensitive ceramics. The high-performance bismuth-free ZnO-Cr2O3-based pressure-sensitive ceramic has high nonlinearity coefficient and breakdown field strength and small leakage current density, and has a wide application prospect in miniaturized electronic circuit systems.

An organic EL element is an organic EL element (10) provided with a laminate held between a pair of electrodes (3), (4), the laminate having an acceptor layer (1) and a donor layer (2) forming an interface with the acceptor layer (1), the acceptor layer (1) containing an acceptor molecule, the donor layer (2) containing a donor molecule that undergoes triplet-triplet annihilation, the acceptor molecule and the donor molecule satisfying a condition related to a prescribed energy level, and the like.

The invention relates to an organic heterojunction-based light-temperature dual-response sensor element, which is prepared from a substrate, a source electrode, a drain electrode, a grid electrode, an organic active layer, a dielectric layer and a device encapsulation layer, and is characterized in that the organic active layer is composed of a Rho group and an imide group in a Rho diimide system organic small molecular structure; the compound has a long conjugated molecular structure, and charge transfer and energy level matching can be effectively promoted. The organic heterojunction structure has the advantages that the organic heterojunction structure has an interpenetrating network form, the donor-acceptor interface area is remarkably increased, so that the charge separation efficiency is enhanced, the carrier mobility is improved, the transconductance, the on-off ratio and the stability of a sensor element are improved, and the organic heterojunction structure has good solution processability and can be applied to the field of sensor devices. The method is suitable for large-area and low-cost flexible electronic manufacturing. The invention provides a new material system for light and temperature dual-response sensor elements, and has wide application prospects in the fields of wearable sensing, Internet of Things, environment monitoring and the like.

The invention relates to the field of organic photoelectric materials, in particular to an organic compound, a mixture and an organic photovoltaic device. The invention provides an organic compound as shown in a general formula (I), the compound has a large conjugate plane, and is beneficial to delocalization of electrons and improvement of the glass transition temperature; meanwhile, close packing like linear molecules is inhibited by the three-dimensional structure, so that excessive crystallization is inhibited; finally, the structure of three electron-withdrawing end groups of the organic compound provided by the invention provides a multi-dimensional electron transport channel, improves the electron mobility and inhibits recombination. Therefore, when the compound is used as an acceptor material to be applied to an organic photovoltaic device, excellent photoelectric conversion efficiency is shown.

The present invention discloses an organic light-emitting diode (OLED), comprising a transparent substrate, an anode, a first organic acceptor layer, a first organic heterojunction, a first organic donor layer, an electron blocking layer, a light-emitting layer, an electron transport layer, a LiF / Al layer, a second organic acceptor layer, a second organic heterojunction, a second organic donor layer, and a cathode, stacked in order from bottom to top. The first organic acceptor layer, the first organic heterojunction, and the first organic donor layer constitute a hole injection layer; the second organic acceptor layer, the second organic heterojunction, and the second organic donor layer constitute an electron injection layer. The present invention has higher charge generation efficiency, overcomes the device's dependence on the electrode work function, and improves device stability.

This invention relates to the field of laser transfer technology, and more particularly to a high-throughput transfer method for solid-state thin films, comprising the following steps: A) preparing a transfer film and a acceptor substrate; the transfer film includes a flexible transparent substrate and a solid-state thin film adhered to the inner surface of the flexible transparent substrate; the thickness of the solid-state thin film is 2–20 μm; B) applying a transfer laser to the transfer film, allowing the transfer laser to pass through the flexible transparent substrate and irradiate the solid-state thin film, causing the solid-state thin film to melt, transfer, and deposit onto the acceptor substrate. The high-throughput transfer method for solid-state thin films proposed in this invention is advantageous in ensuring high-throughput transfer and achieving high-efficiency forming while not only improving transfer stability but also reducing application costs, thus overcoming the shortcomings of existing technologies.

The invention relates to the technical field of photoelectric materials, in particular to an asymmetric Y-series receptor and fluorene coupled compound and a preparation method and application thereof. The invention provides a fluorenyl-cyclic structure-asymmetric Y6 ternary fusion structure with a clear structure-function relationship. The rigid plane structure of fluorene provides excellent hole transport capability and inherent thermal form stability for molecules. The asymmetric Y6 can effectively regulate and control the energy level structure of molecules and enhance intramolecular charge transfer, and meanwhile, the asymmetric structure of the asymmetric Y6 is beneficial to inhibition of excessive crystallization and optimization of phase separation. The combination of the two can generate a synergistic effect. The fluorene unit can compensate voltage loss caused by introduction of bromine, and realizes wider spectral absorption and higher charge generation and transmission efficiency through combined action. A cyclic structure is introduced into a fluorene core, so that the LUMO energy level of the whole molecular receptor is effectively increased. The compound as an acceptor material is excellent in performance, has a three-dimensional charge transfer characteristic, and is beneficial to improvement of charge mobility.

The present invention provides a nitride semiconductor device that can introduce Mg at a high concentration while keeping the threshold low. [Solution] The normally-off transistor of the nitride semiconductor device comprises a gate insulating film provided on the first surface side of the nitride semiconductor substrate, a gate electrode provided on the gate insulating film, a p-type layer facing the gate electrode with the gate insulating film in between, and a polarization-doped layer facing the gate electrode with the p-type layer in between and in contact with the p-type layer. The Mg concentration of the p-type layer is 1 × 10⁻⁶ 18 cm -3 The above 1 x 10 20 cm -3 The following applies: The effective acceptor concentration in the p-type layer is Np(cm -3 Let the thickness of the p-type layer be dp (nm) and the polarization density of the polarization-doped layer be Npol (cm -3 If we let ) be the thickness of the polarization-doped layer be dpol (nm) and the aluminum (Al) concentration on the surface of the polarization-doped layer be Nal, then equations (1) and (2) hold true, respectively.