287 results about "Polycrystalline material" patented technology

The invention discloses a method and a device for growing a cadmium zinc telluride single crystal, and is characterized in that the method comprises the following steps: (1) putting a cadmium zinc telluride polycrystal ingot into a pyrolytic boron nitride crucible, the cadmium zinc telluride polycrystal ingot is obtained by a preset temperature gradient synthesis method, and has [111] crystal orientation cluster crystal grains in the growth direction; (2) putting the pyrolytic boron nitride crucible into a vacuum closed quartz container, controlling a six-temperature-zone growth furnace through a computer to complete the melting process of a polycrystalline material, and before formal growth, forming a solid-liquid interface distribution structure in which polycrystals are not melted and the rest parts are completely melted at the center of the bottom, wherein the diameter of the solid-liquid interface distribution structure is not less than 30mm; (3) after heat preservation is conducted for a preset time, two-step cooling is achieved in a VGF mode; in the first cooling stage, an initial temperature gradient is formed, and after heat preservation is conducted for a preset time, elimination, merging and growth of [111] crystal nuclei are completed; in the second cooling stage, stable and continuous propulsion of a solid-liquid interface is completed, and continuous growth of single crystals is achieved; and finally, cooling to room temperature to obtain the cadmium zinc telluride single crystal. According to the method, the effect of growing the cadmium zinc telluride crystal with high single crystal rate under the seed crystal-free condition is realized.

The invention provides a modified lithium-rich manganese-based positive electrode material, a preparation method thereof and a lithium ion battery, and relates to the technical field of new energy. According to the modified lithium-rich manganese-based positive electrode material disclosed by the invention, multi-element point position doping is carried out on a base material to enhance the structural stability of a polycrystalline material, inhibit transition metal ion migration and interlayer dislocation, improve the internal lattice strength and manufacture a stable base material core; the heterostructure layer can greatly improve the surface structure phase change and transition metal dissolution of the material surface under high voltage, the stability of the surface of the matrix material is improved, and the rate capability of the material can be improved by the in-situ generated three-dimensional ion channel; the coating layer can effectively reduce side reaction of a solid-liquid interface, improve dissolution of metal ions on the surface and improve the cycle performance of the material; in a word, the internal structure and the surface of the material are effectively modified mainly through three means of doping, interface structure design and coating, the multiplying power of the material can be greatly improved, and the long-term service life of the material can be greatly prolonged.

The invention discloses a method and system for constructing an elastic viscoplastic multi-scale constitutive model of a polycrystalline material, and the method comprises the steps: building a single crystal scale constitutive model on the basis of a representative volume element model RVE of the polycrystalline material, obtaining a relation between a stress rate and a strain rate of a single crystal grain, and then obtaining a relation between a stress rate and a strain rate of an RVE scale; establishing a relationship among an affine strain rate, a stress local tensor and a strain local tensor; setting the initial strain increment of a single crystal grain as the overall strain increment, and obtaining the stress increment of the RVE scale through finite element analysis iterative calculation. The method is suitable for solving the deformation problem under the complex boundary condition, the relation between the strain increment and the stress increment is defined through the algorithm tangent operator and the affine strain increment, and the calculation accuracy is improved.

The invention relates to an intermediate infrared holmium-praseodymium-calcium-magnesium-zirconium co-doped gadolinium-gallium garnet laser crystal as well as a preparation method and application thereof, and belongs to the technical field of single crystals or uniform polycrystalline materials with certain structures. The mid-infrared holmium-praseodymium-calcium-magnesium-zirconium co-doped gadolinium-gallium garnet laser crystal comprises a host crystal, active ions, de-active ions and auxiliary ions, the host crystal is a gadolinium gallium garnet crystal, the activating ion is Ho < 3 + >, the deactivating ion is Pr < 3 + >, and the auxiliary ions at least comprise Ca < 2 + >, Mg < 2 + > and Zr < 4 + >; the doping concentration of Pr < 3 + > is greater than or equal to 0.05 at%. The mid-infrared holmium-praseodymium-calcium-magnesium-zirconium co-doped gadolinium-gallium garnet laser crystal has the advantages of low laser threshold and high laser output power and efficiency.

The invention relates to an indium phosphide crystal containing doped elements, a single crystal wafer and a preparation method of the indium phosphide crystal. Specifically, the invention relates to an indium phosphide crystal containing a doped element, the doped element is doped in an indium phosphide crystal growth melt or in indium phosphide polycrystalline material synthesis, and the indium phosphide crystal is an S-doped or Sn-doped N-type indium phosphide single crystal or a Zn-doped P-type indium phosphide single crystal. The doped element is one or more elements, and the segregation coefficient of the doped element in indium phosphide is not greater than 0.05; and the content of the doped element in the indium phosphide crystal is 30 ppb to 30 ppm. The invention also relates to a method for preparing the indium phosphide crystal containing the doped elements, a method for preparing a single crystal wafer and a device prepared from the indium phosphide single crystal. The indium phosphide crystal containing the doped elements obtained according to the invention is high in single crystal yield.

The present invention relates to a ternary co-blended lithium iron manganese phosphate material and a preparation method and application thereof, wherein the ternary co-blended lithium iron manganese phosphate material comprises a ternary single crystal material, a ternary polycrystalline material and lithium iron manganese phosphate; the particle size distribution of the ternary single crystal material is between that of the ternary polycrystalline material and the lithium iron manganese phosphate. The particle size distribution of the ternary single crystal material in the present invention is between that of the large particles of the ternary polycrystalline material and the small particles of the lithium iron manganese phosphate. After blending, the particle size distribution of the material is wider, and particles with relatively small particle sizes can fill the gaps between the large particles, thereby improving the compaction density of the material to a certain extent; according to the particle size distribution, the overall particle size distribution of the lithium iron manganese phosphate material co-blended with the ternary polycrystalline and ternary single crystal materials becomes wider, thereby improving the stability of lithium ions in the process of charging and discharging in and out of the lattice of the ternary material, providing elastic strain for the material to be impacted by external forces, thereby improving the safety and cycle performance of the material.

The invention provides a positive electrode material, a preparation method thereof and a lithium ion battery, and relates to the technical field of lithium ion batteries. The positive electrode material comprises a single crystal material and a polycrystalline material, the single crystal material is composed of primary particles, and the polycrystalline material is composed of secondary spherical particles formed by gathering the primary particles; the average particle size D of the positive electrode material satisfies D = D1 * K + D2 * L, where 3 [mu] m < D1 < 9 [mu] m, 10 [mu] m < D2 < 20 [mu] m, 0 < = K < = 1, 0 < = L < = 1, and K + L = 1. The preparation method of the positive electrode material comprises the following steps: respectively preparing a polycrystalline positive electrode material and a single-crystal positive electrode material from raw materials including a positive electrode precursor, a lithium source, a doping agent and a coating agent; and mixing in proportion to obtain the positive electrode material. The polycrystalline material and the single crystal material are mixed, the capacity of the polycrystalline material is exerted, meanwhile, the high compressive strength of the single crystal material is considered, gas production of the positive electrode material is inhibited, and the safety performance of the lithium ion battery is improved.

The invention relates to a polycrystal Cs2ZnI4 material with low thermal conductivity, a single crystal Cs2ZnI4 material and application of the polycrystal Cs2ZnI4 material and the single crystal Cs2ZnI4 material. The polycrystal Cs2ZnI4 material is prepared by the following method: uniformly mixing and grinding CsI and ZnI2, and then sequentially performing high-temperature melting, quenching and annealing in a vacuum environment to obtain the polycrystal Cs2ZnI4 material with low thermal conductivity, the thermal conductivity of the polycrystalline Cs2ZnI4 material at room temperature is not greater than 0.17 W / m <-1 > K <-1 >. The single crystal Cs2ZnI4 material is prepared by adopting the following method: growing a polycrystal Cs2ZnI4 material in a vacuum environment by adopting a vertical gradient freezing method to obtain the single crystal Cs2ZnI4 material with low thermal conductivity. Compared with the prior art, the polycrystal Cs2ZnI4 material and the single crystal Cs2ZnI4 material prepared by the invention both show extremely low thermal conductivity and structural stability, and can be applied to the fields of electronic equipment, thermoelectric materials or aerospace and the like.

Disclosed herein are methods for setting the radiation sensitivity and operational temperature range of ion-conducting polycrystalline radiation detectors. Disclosed herein are material fabrication methods for setting the ion-conducting polycrystalline microstructure and the grain boundary ion blocking characteristics in ion-conducting polycrystalline materials. The methods may include introducing a selected precursor element into the grain boundaries of the ion-conducting polycrystalline material. These methods may allow for the device detection threshold, dynamic range, and / or operational temperature range to be adjusted for ion-conducting polycrystalline radiation detectors. The methods disclosed herein allow for the design of high-sensitivity and high-performance radiation detectors that are low cost, non-toxic, environmentally robust, scalable, and able to operate in harsh environments (e.g., high temperature, high humidity, pressure, and / or corrosive).

The invention relates to the technical field of thermoelectric semiconductor materials, and discloses a CuAgSe-based thermoelectric semiconductor crystal and a preparation method thereof.The CuAgSe-based thermoelectric semiconductor crystal is prepared from elementary substance Cu, elementary substance Ag and elementary substance Se through melting treatment and a Bridgman growth method; compared with a CuAgSe-based thermoelectric semiconductor crystal prepared by a pressure sintering method, the material has the advantages of high conductivity, slightly low Zebeck coefficient, equivalent heat conductivity, high thermoelectric figure of merit and high thermoelectric performance; according to the method, the cooling gradient and the movement rate of a polycrystalline material in the cooling gradient are controlled to enable the crystal to grow into the CuAgSe crystal with high single orientation, the content of a second phase in the crystal can be remarkably reduced by controlling the cooling gradient, the CuAgSe crystal with high single orientation can be directly obtained, and the second phase does not need to be removed; and the utilization rate of the CuAgSe polycrystalline raw material is obviously improved.

New high entropy ceramics comprising rare earth oxides are disclosed. The new high entropy ceramic materials generally contain from five to ten different rare earth oxides with each of the rare earth oxides comprising a different rare earth element. The new ceramic materials may be substantially single-phase, polycrystalline materials. The new ceramic materials may realize improved properties, such as plasma etch resistance, among others.

The invention discloses a laser single crystal optical fiber doped with ions in a gradient manner and a preparation method of the laser single crystal optical fiber, when the single crystal optical fiber is prepared, firstly, raw materials with different doping concentrations are uniformly mixed respectively, then the raw materials are pressed into sheets respectively, the sheets are pressed for the second time to enhance compactness, then the pressed sheets are sintered to obtain a polycrystal material, and the polycrystal material is sintered to obtain the laser single crystal optical fiber doped with ions in a gradient manner. The preparation method comprises the following steps: respectively grinding a polycrystalline material until the polycrystalline material passes through a 400-mesh sieve, filling polycrystalline material powder into a strip balloon in a gradient segmentation manner, compacting and sealing, pressing and sintering to obtain a ceramic material rod, cutting the ceramic material rod into a ceramic square rod, and performing seeding growth by adopting a laser heating base method and taking the ceramic square rod as a source material rod to obtain the gradient ion-doped laser single crystal optical fiber. Compared with the prior art that the laser single crystal fiber doped with the ions in the gradient mode is prepared through a welding process, the method is low in process difficulty, welding interface diameter fluctuation does not need to be accurately controlled, the yield is high, the procedure is simple, and the production efficiency is high.

The invention discloses a method for preparing a tellurium-indium-lead polycrystal material for single crystal growth by a horizontal gradient crystallization method, and relates to a preparation method of the tellurium-indium-lead polycrystal material. The technical problems that an existing PIT single crystal is serious in cracking and high in optical absorption are solved. The method comprises the following steps: weighing a Pb source, an In source, a Te source and In2Te3 raw materials, putting the raw materials into a crucible, putting Te providing atmosphere pressure into another crucible, putting the two crucibles at two ends of a quartz tube, filling inert gas, and sealing by melting; the method comprises the following steps: putting a quartz tube into a double-temperature-zone horizontal tube furnace, putting a raw material crucible into a high-temperature zone, putting another crucible into a low-temperature zone, and carrying out a reaction stage, a homogenization stage, a gradient crystallization stage and a cooling stage to obtain the tellurium-indium-lead polycrystal material. The polycrystalline material is used for growing a single crystal, the optical absorption of a wafer with the thickness of 4.385 mm and double polished faces is smaller than 0.17 cm <-1 > at the 2.09 mu m position, middle and far infrared laser can be output by means of laser pumping, and the polycrystalline material is used in the fields of industry, medical treatment and energy.

The invention discloses a polycrystalline material microstructure crack evolution simulation and mechanical property prediction method and system. The method comprises the following steps: establishing a voronoi geometric model of a polycrystalline material containing grain characteristics and microstructure defect characteristics; carrying out spatial distribution modeling on the mechanical property parameters of the polycrystalline material based on a probability statistics theory; importing the voronoi geometric model of the polycrystalline material into a multi-physics field simulation software platform, establishing a complete simulation geometric model for crack prediction based on a phase field fracture theory, and performing phase field solution; setting corresponding material parameters according to the material attributes; and setting corresponding boundary conditions in simulation software to simulate a four-point bending experiment, solving a phase field fracture control equation by utilizing a finite element algorithm, capturing a change rule of a crack propagation path, and recording key mechanical data. According to the method, the polycrystalline Voronoi model is constructed, spatial distribution modeling is carried out on the mechanical parameters of the material in combination with the probability statistics theory, and the non-uniform characteristic of the actual material can be reflected more truly.

The invention relates to the technical field of preparation of single crystal materials, in particular to a low-cost lead-free piezoelectric single crystal with high piezoelectric response and a preparation method, the lead-free piezoelectric single crystal is of a lead-free perovskite structure, the chemical general formula of the lead-free piezoelectric single crystal is xBi < 0.5 > Na < 0.5 > TiO < 3-y > Bi < 0.5 > K < 0.5 > TiO < 3-(1-x-y) Bi < 0.5 > Li < 0.5 > TiO < 3 >, x is equal to 0-1, y is equal to 0-0.2, and x is equal to 0-1. The preparation method comprises synthesis of a multi-component lead-free precursor polycrystalline material, interface construction of a seed crystal and a polycrystalline substrate, and a high-temperature solid-phase epitaxial growth process. The components and various key process parameters of the material involved in the invention are finely controlled, the process window in the preparation process is narrow, reverse analysis is not easy to occur, and the preparation method has a remarkable technical barrier and is suitable for industrial popularization as a key preparation technology of the high-performance lead-free piezoelectric single crystal material.

The invention discloses a preparation method of a lithium cobalt oxide positive electrode material, the lithium cobalt oxide positive electrode material and a lithium battery, and relates to the technical field of lithium ion batteries. The method comprises the following steps: firstly, preparing a polycrystalline lithium cobalt oxide defective product and a single-crystal lithium cobalt oxide defective product, and respectively introducing doping elements in a first additive and a second additive into the polycrystalline lithium cobalt oxide defective product and the single-crystal lithium cobalt oxide defective product; a polycrystalline lithium cobalt oxide defective product, a third additive and a fourth additive are mixed and sintered, a sintering aid (the third additive contains a doping element M1) and a high-valence transition metal compound (the fourth additive contains a doping element M2) are matched, a high-melting-point Li-Co-M1-M2 phase is generated at the grain boundary, the grain boundary binding energy is improved, and therefore the compressive strength of the polycrystalline material is improved. After the grain boundary optimized lithium cobalt oxide defective product and the monocrystal lithium cobalt oxide defective product are graded, the lithium cobalt oxide positive electrode material with high compaction density can be obtained, and meanwhile, the positive electrode material can give consideration to rate performance and cycle performance.

The invention discloses a twin crystal nucleation position and variant selection prediction method based on machine learning, and belongs to the crossing field of material science and machine learning. The method comprises the following steps: acquiring microscopic structure data of a deformation material through electron back scattering diffraction, and constructing a multi-dimensional data set containing crystal grain parameters, crystal boundary parameters and deformation mechanism parameters by taking crystal grains and a certain crystal boundary combination as an analysis unit; and then modeling and predicting the twin crystal nucleation position and variant selection respectively by adopting a hierarchical machine learning modeling strategy. According to the method, the twinning behavior in the polycrystalline material can be efficiently and accurately predicted, and theoretical support and a technical path are provided for high-performance metal material design and plastic deformation mechanism research.

A latent heat storage includes a ceramic part, formed of a polycrystalline material, and including a closed space famed therein, and a metal part provided inside the closed space, and including copper.

The invention relates to a sulfur-antimony-lanthanum-barium compound, a sulfur-antimony-lanthanum-barium mid-far infrared birefringent optical crystal and a preparation method and application thereof, relates to a mid-far infrared birefringent crystal and a preparation method and application thereof, and aims to solve the problem of low birefringence of the existing mid-far infrared crystal, the sulfur-antimony-lanthanum-barium compound has the chemical formula of Ba2La2Sb4S10 (S2) and the molecular weight of 1424.22, is crystallized in a monoclinic system, and has the molecular weight of 294nm. The space group is P21 / c, and the cell parameters are as follows: a = 8.6373 (5), b = 14.7336 (9), c = 15.9161 (9), alpha = gamma = 90 degrees, and beta = 92.661 (2) degrees. Preparing a compound or a polycrystal material by using a high-temperature solution or a solid-phase method; a polycrystalline material is used for growing a single crystal, the birefringence of the single crystal is 0.53 at the position of 1064 nm, the single crystal has large birefringence within the range of 1-14 microns, and the single crystal is used in an optical isolator, a circulator, a beam shifter, an optical polarizer or an optical modulator.

The embodiment of the invention discloses a system and method for rapidly representing a grain boundary network by using a series of transmission electron microscope dark field images, and belongs to the field of polycrystalline material microstructure characterization, and the method comprises the following steps: collecting series of dark field images at different positions on a plurality of diffraction rings; correcting drifting of the series of dark field images; for any position in the dark field image, taking the intensity change of the series of dark field images at the same pixel as the feature of the pixel, and calculating the data similarity of the pixel and the features corresponding to a plurality of adjacent pixels; and synthesizing and visualizing the similarity between any pixel and a plurality of adjacent pixels to obtain the form of the crystal boundary network. The method for rapidly characterizing the grain boundary network by using the series of transmission electron microscope dark field images provided by the embodiment of the invention has the advantages of high spatial resolution, insensitivity to crystal defects, small irradiation damage and capability of rapidly and accurately obtaining the grain boundary network, and can support further enrichment of material characterization technologies and provide technical support for development of crystal materials.

New substantially single-phase polycrystalline materials are disclosed. The new substantially single-phase polycrystalline materials generally include from 0.01-20 mol. % zirconia, at least 80 mol. % of one or more rare earth oxides (REO), and 40 to 7000 ppm aluminum by weight, wherein the substantially single-phase polycrystalline material comprises at least 95 wt. % of a solid-solution of REO-zirconia as measured by x-ray diffraction. The new substantially single-phase polycrystalline materials may realize a high density, such as a density of at least 95% of theoretical density, or higher. The new substantially single-phase polycrystalline materials may be in the form of a semiconductor component, including those suited for use in a plasma chamber environment.

The invention provides a solar cell and a manufacturing method thereof, and relates to the field of solar cells. The invention aims to solve the problem that the passivation influence of laser on a textured P region is relatively large. The manufacturing method comprises the steps that a semiconductor substrate of a first conduction type is provided, the back face of the semiconductor substrate comprises first parts and second parts which are alternately arranged, and third parts located between the adjacent first parts and second parts; the first part comprises a first sub-part and a second sub-part, and the second sub-part is adjacent to the third part; forming a diffusion layer and a first mask layer; forming a tunneling passivation layer; forming a doped polycrystalline material layer and a second mask layer; removing the second mask layer on the third part and the second sub-part by utilizing first laser etching; and exposing the surface of the semiconductor substrate corresponding to the third part and the second sub-part by adopting a wet etching mode to form a step-shaped spacing structure. The manufacturing method has no adverse effect on passivation of the area where the emitter is located.

The invention relates to the technical field of grain size modeling, in particular to a pseudo-random high-fidelity modeling method for a multiphase polycrystalline material grain size microstructure, which comprises the following steps of: counting the size distribution, orientation distribution and orientation difference distribution among grains of each phase; carrying out statistics on size distribution, quantity proportion and orientation difference distribution between the categories of each category; constructing a geometric boundary; generating a core crystal grain reference point in the geometric boundary, arranging other crystal grain reference points in the residual space, and determining a growth weight according to a size relationship between adjacent crystal grains; and generating a grain size microstructure geometric model. According to the method, the weighted Voronoi method is introduced, and the weight is determined according to the spatial position relationship of the reference points and the expected growth size (target grain size), so that the growth rates of different grains in different directions are different, and the competitive growth behavior of the grains in an actual material is truly reproduced; the problem that in existing Voronoi modeling, the growth speed of crystal grains in all directions is uniform is solved, and the obtained microstructure model is beneficial for improving the simulation precision of the real mechanical behavior of the material.

The invention discloses a lithium tantalate wafer and a preparation method of the lithium tantalate wafer, the lithium ion concentration in the lithium tantalate wafer is 49.6%-49.75%, the preparation method comprises the following steps: uniformly putting 50-200g of lithium tantalate polycrystalline material into the bottom of a first crucible; placing two platinum wires above the lithium tantalate polycrystal material, and placing the same-component lithium tantalate wafer on the platinum wires; placing the sealed first crucible in a second crucible, wherein the bottom of the second crucible is fully paved with lithium tantalate polycrystal materials; and placing the second crucible in a heat treatment furnace, and carrying out heat treatment at 1190-1320 DEG C for 10-150 hours for diffusion to obtain the finished lithium tantalate wafer. The lithium content in the same-component lithium tantalate wafer is adjusted by adjusting the lithium ion concentration and quality in the lithium tantalate polycrystal material, so that the lithium tantalate wafer with the lithium ion concentration of 49.6%-49.75% is prepared, and the acoustic performance of the lithium tantalate wafer is improved.

A coated abrasive article comprising a backing, an adhesive layer disposed in a discontinuous distribution on at least a portion of the backing, wherein the discontinuous distribution comprises a plurality of adhesive contact regions and at least one shaped abrasive particle is disposed on a majority of each of the discrete adhesive contact regions, wherein at least 50% of the shaped abrasive particles comprise a predetermined side orientation and have a tilt angle of at least 45 degrees, wherein the shaped abrasive particles comprise a polycrystalline material and are free of binder, wherein the first plurality of discrete adhesive contact regions comprise a predetermined two-dimensional shape as viewed from above, and wherein each of the discrete contact regions comprises a length, a width, or a combination thereof that substantially corresponds to a dimension of the at least one abrasive particle.

A SAW resonator with reduced spurious modes is provided. The resonator comprises a (111) silicon carrier substrate (CS), an electrode structure (ES) and a piezoelectric layer (PIL). The carrier substrate has a crystal orientation with the Euler angles (−45°±10°; −54°±10°; 60°±30°) and the piezoelectric layer comprises LiTaO3 and has a crystal orientation with the Euler angles (0°; 56°±8°; 0°). There may be intermediate layers (IL1, IL2) of SiO2 and amorphous or polycrystalline materials. In addition a silicon nitride layer is provided as passivation (PAL). Electrodes are made of aluminum. Thicknesses of all layers are selected in particular ranges to optimize SAW behaviour.

A particulate cathode active material comprising (A) a base material according to the general formula Li1 + xTM1-xO2, where TM is a combination of Ni with at least one of Mn, Co and Al, and optionally at least another metal selected from the group consisting of Mg, Ti, Zr, Nb, Ta and W, and x is in the range of 0 to 0.2, and (B) crystallites of one or more cobalt compounds, where at least some of the cobalt is in the oxidation state of + III, where the base material (A) is a polycrystalline material, where x is greater than 0 and less than 1. The secondary particles of which consist of primary particles, and crystallites (B) of a cobalt compound are coated on the outer surfaces of these secondary particles, and one or more cobalt compounds are enriched at the surfaces of the primary particles in the voids between adjacent primary particles, and wherein 90% to 99.5% of the secondary particles exhibit such cobalt compound enrichment, all the detection results are determined through EDX and SEM / TEM imaging.

To provide a surge suppression component capable of suppressing the decline in reliability while maintaining a satisfactory inhibitory effect.SOLUTION: A surge suppression component 1 includes a base material 10 and at least a pair of electrodes. At least a part of the electrodes is placed on the surface or inside of the base material 10. The base material 10 includes a functional part 11 with a void between the pair of electrodes, which is made of polycrystalline material that shows voltage nonlinearity. At least one of the pair of electrodes includes multiple insulating particles 20 at least inside the electrode and near the interface between the electrode and the functional part 11.SELECTED DRAWING: Figure 1

The present disclosure relates to a layered seed for growing a volume mono crystal by gas phase growth in a direction of growth (Y) in a crucible (1200). The layered seed comprises a monocrystalline growing layer (110) with a growing surface (112) for growing the volume mono crystal and an opposing heat spreader facing surface (114) for coupling the growing layer (110) to a heat spreader layer (140). The layered seed further comprises the heat spreader layer (140) with a growing layer facing surface (144) for coupling to the heat spreader facing surface (114) and an opposing mounting surface (142) for mounting the heat spreader layer (140) to the crucible (1200), wherein the heat spreader layer (140) comprises a polycrystalline material having thermally coupled grains (146) that are piled in the direction of growth (Y), the piled grains (146) for equalizing hot spots of the crucible thermally coupled to the mounting surface (142).

The invention discloses a diamond polycrystalline substrate with high heat conductivity and good light transmission and application, and belongs to the technical field of diamond polycrystalline materials. The heat conductivity of the diamond polycrystalline substrate at any position is greater than or equal to 1560 W / (m.K); and the light transmittance at any position is greater than or equal to 48%. According to the diamond polycrystalline substrate, the heat conductivity is improved, meanwhile, amorphous carbon can be prevented from being formed, black spots do not exist in the diamond polycrystalline substrate, and therefore the heat conductivity and the light transmittance are both improved.