WO2018120516A1 - 一种纳米材料、制备方法及半导体器件 - Google Patents

一种纳米材料、制备方法及半导体器件 Download PDF

Info

Publication number
WO2018120516A1
WO2018120516A1 PCT/CN2017/080621 CN2017080621W WO2018120516A1 WO 2018120516 A1 WO2018120516 A1 WO 2018120516A1 CN 2017080621 W CN2017080621 W CN 2017080621W WO 2018120516 A1 WO2018120516 A1 WO 2018120516A1
Authority
WO
WIPO (PCT)
Prior art keywords
precursor
nanomaterial
compound
zinc
cadmium
Prior art date
Application number
PCT/CN2017/080621
Other languages
English (en)
French (fr)
Inventor
刘政
杨一行
钱磊
Original Assignee
Tcl集团股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tcl集团股份有限公司 filed Critical Tcl集团股份有限公司
Publication of WO2018120516A1 publication Critical patent/WO2018120516A1/zh

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K2102/00—Constructional details relating to the organic devices covered by this subclass
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/115—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising active inorganic nanostructures, e.g. luminescent quantum dots
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/10—Deposition of organic active material
    • H10K71/16—Deposition of organic active material using physical vapour deposition [PVD], e.g. vacuum deposition or sputtering
    • H10K71/164—Deposition of organic active material using physical vapour deposition [PVD], e.g. vacuum deposition or sputtering using vacuum deposition

Definitions

  • the invention relates to the field of quantum dots, in particular to a nano material, a preparation method and a semiconductor device.
  • Quantum dots are special materials that are limited to the order of nanometers in three dimensions. This remarkable quantum confinement effect makes quantum dots have many unique nano properties: the emission wavelength is continuously adjustable, and the emission wavelength is narrow. Wide absorption spectrum, high luminous intensity, long fluorescence lifetime and good biocompatibility. These characteristics make quantum dots have broad application prospects in the fields of flat panel display, solid state lighting, photovoltaic solar energy, and biomarkers. Especially in flat panel display applications, Quantum dot light-emitting diodes (QLEDs) based on quantum dot materials have been displaying image quality, device performance, and performance by virtue of the characteristics and optimization of quantum dot nanomaterials. Manufacturing costs and other aspects have shown great potential.
  • QLEDs Quantum dot light-emitting diodes
  • quantum dots have been researched and developed as a classic nanomaterial for more than 30 years, the research time of utilizing the excellent luminescent properties of quantum dots and applying them as nanomaterials in QLED devices and corresponding display technologies is still short; Therefore, the development of most of the current QLED devices And the research is based on the quantum dot material of the existing classical structure system.
  • the corresponding standard of screening and optimization of the quantum dot material is basically based on the luminescent properties of the quantum dot itself, such as the luminescence peak width of the quantum dot, the solution quantum yield, and the like. .
  • the above quantum dots are directly applied to the QLED device structure to obtain corresponding device performance results.
  • QLED devices and corresponding display technologies are a complex optoelectronic device system, and there are many factors that affect the performance of the device.
  • the quantum dot material that is the core luminescent layer material
  • the quantum dot performance metrics that need to be weighed are much more complicated.
  • quantum dots exist in the form of solid-state films of quantum dot luminescent layers in QLED devices. Therefore, the luminescent properties of quantum dot materials originally obtained in solution may show significant differences after forming solid films: for example In the solid film, the luminescence peak wavelength will have different degrees of red shift (moving to long wavelength), the luminescence peak width will become larger, and the quantum yield will be reduced to different extents, that is, the quantum luminescent material has excellent luminescence in solution. Performance is not fully inherited into the quantum dot solid state film of QLED devices. Therefore, in designing and optimizing the structure and synthetic formulation of quantum dot materials, it is necessary to simultaneously consider the optimization of the luminescent properties of the quantum dot material itself and the luminescence inheritance of the quantum dot material in the state of the solid film.
  • the luminescence of quantum dot materials in QLED devices is achieved by electro-excitation, that is, energization of holes and electrons from the anode and cathode of the QLED device, respectively, and the transport of holes and electrons through the corresponding functional layers in the QLED device.
  • electro-excitation that is, energization of holes and electrons from the anode and cathode of the QLED device, respectively, and the transport of holes and electrons through the corresponding functional layers in the QLED device.
  • photons are emitted by means of radiation transitions to achieve luminescence. It can be seen from the above process that the luminescent properties of the quantum dots themselves, such as luminescence efficiency, only affect the efficiency of the radiation transition in the above process, and the overall luminescence efficiency of the QLED device is also affected by the charge of holes and electrons in the quantum dot material in the above process.
  • quantum dot materials Injection and transport efficiency, relative charge balance of holes and electrons in quantum dot materials, recombination of holes and electrons in quantum dot materials, and the like. Therefore, in designing and optimizing the structure of quantum dot materials, especially the fine core-shell nanostructures of quantum dots, it is also necessary to consider the electrical properties of quantum dots after forming solid films: for example, charge injection and conduction properties of quantum dots, fineness of quantum dots. Energy band structure, exciton lifetime of quantum dots, etc.
  • quantum dot solutions such as quantum dot solutions.
  • dispersible solubility of the printing ink the colloidal stability, the print film forming property, and the like.
  • development of quantum dot materials is also coordinated with the other functional layer materials of QLED devices and the overall fabrication process and requirements of the devices.
  • the traditional quantum dot structure design which only considers the improvement of the quantum dot self-luminescence performance, can not meet the comprehensive requirements of QLED devices and corresponding display technologies for the optical properties, electrical properties and processing properties of quantum dot materials.
  • the fine core-shell structure, composition, energy level, etc. of quantum dot nanomaterials need to be tailored to the requirements of QLED devices and corresponding display technologies.
  • a semiconductor shell layer containing another semiconductor material can be grown on the outer surface of the original quantum dot to form a core-shell structure of the quantum dot, which can significantly improve the luminescent properties of the quantum dot and increase the quantum. Point stability.
  • the quantum dot materials that can be applied to the development of high-performance QLED devices are mainly quantum-shells with quantum-shell structures, the core and shell components are fixed separately and the core-shell has a clear boundary, such as a quantum dot with a CdSe/ZnS core-shell structure (J. Phys). .Chem., 1996, 100(2), 468–471), Quantum Dots with CdSe/CdS Core-Shell Structure (J. Am. Chem. Soc.
  • quantum dots of the core-shell structure described above partially improve the performance of the quantum dots, the luminescent properties of the quantum dots themselves need to be improved, both in terms of design ideas and optimization schemes, and the luminescence properties have yet to be improved. Consider the special requirements of semiconductor devices for other aspects of quantum dot materials.
  • the object of the present invention is to provide a nano material, a preparation method and a semiconductor device, which aim to solve the problem that the luminescent properties of the existing nano materials need to be improved and the requirements of the semiconductor device for the nano material cannot be satisfied. .
  • the nano material comprises N nanostructure units arranged in a radial direction, wherein N ⁇ 2;
  • the nanostructure unit includes A1 and A2 types, and the A1 type is a uniform composition structure having uniform energy level widths in a radial direction; and the A2 type is a graded alloy group having a wider outer energy level width in a radial direction.
  • the interior of the nanomaterial consists of at least one layer of A1 type nanostructure unit, the exterior of which is composed of at least one layer of A2 type nanostructure unit;
  • the energy level width of the nanostructure unit near the center of the nano material is not greater than the energy level width of the nanostructure unit away from the center of the nano material, and the adjacent graded alloy composition structure
  • the energy levels of the nanostructure units are continuous.
  • the nanomaterial wherein the A1 type quantum dot structural unit is a uniform alloy composition structure comprising Group II and Group VI elements, and the A2 type quantum dot structural unit is composed of Group II and Group VI elements.
  • Gradient alloy composition structure the components are all alloy components; and for the quantum dot structural unit of the uniform component structure, the composition may be an alloy component or an alloy.
  • a component but the preferred component of the present invention is an alloy component, that is, the uniform component structure is a uniform alloy component structure, and more preferably, it comprises a Group II and Group VI element, and the subsequent embodiments of the present invention each have a uniform alloy group.
  • the substructure is explained as an example, but it is obvious that a uniform composition of the non-alloy can also be carried out.
  • the nano material wherein the alloy component of the A1 type nanostructure unit is Cd x0 Zn 1 ⁇ x0 Se y0 S 1 ⁇ y0 , where 0 ⁇ x0 ⁇ 1, 0 ⁇ y0 ⁇ 1, and x0 and Y0 is not 0 at the same time and is 1 at the same time, and x0 and y0 are fixed values in the corresponding structural unit of the A1 type.
  • the nano material wherein the alloy composition of the A2 type nanostructure unit is Cd x1 Zn 1 ⁇ x1 Se y1 S 1 ⁇ y1 , where 0 ⁇ x1 ⁇ 1, 0 ⁇ y1 ⁇ 1, and x1 and Y1 is not 0 at the same time and 1 at the same time.
  • the alloy component of the A2 type is Cd x A Zn 1 ⁇ x A Se y A S 1 ⁇ y A
  • the alloy composition of the B point is Cd x B Zn 1 ⁇ x B Se y B S 1 ⁇ y B
  • point A is closer to the center of the nanomaterial than point B
  • the composition of points A and B satisfies: x A > x B , y A > y B.
  • nanomaterial wherein the nanostructure unit comprises a 2-20 layer monoatomic layer, or the nanostructure unit comprises a 1-10 layer cell layer.
  • nanomaterial wherein a continuous alloy composition structure is formed between two monoatomic layers at the interface of adjacent nanostructure units in a radial direction, or a junction of adjacent nanostructure units in a radial direction A continuous alloy component structure is formed between the two cell layers.
  • the nano material wherein the nano material has an emission peak wavelength ranging from 400 nm to 700 nm.
  • the nano material wherein the nano-material has a half-peak width of 12 nm to 80 nm.
  • a method for preparing a nanomaterial as described above comprising the steps of:
  • a cation exchange reaction occurs between the first compound and the second compound to form a nanomaterial, and the wavelength of the luminescence peak of the nanomaterial is unchanged first, followed by a blue shift.
  • the method for preparing a nano material wherein the first compound and/or the cationic precursor of the second compound comprises a precursor of Zn, and the precursor of the Zn is dimethyl zinc, diethyl Zinc, zinc acetate, zinc acetylacetonate, zinc iodide, zinc bromide, zinc chloride, zinc fluoride, zinc carbonate, zinc cyanide, zinc nitrate, zinc oxide, zinc peroxide, zinc perchlorate, zinc sulfate At least one of zinc oleate or zinc stearate.
  • the method for preparing a nano material wherein the first compound and/or the cationic precursor of the second compound comprises a precursor of Cd, and the precursor of the Cd is dimethyl cadmium, diethyl Cadmium, cadmium acetate, cadmium acetylacetonate, cadmium iodide, cadmium bromide, cadmium chloride, cadmium fluoride, cadmium carbonate, cadmium nitrate, cadmium oxide, cadmium perchlorate, cadmium phosphate, cadmium sulfate, cadmium oleate or At least one of cadmium stearate.
  • the method for preparing a nano material wherein the anion precursor of the first compound and/or the second compound comprises a precursor of Se, and the precursor of the Se is Se ⁇ TOP, Se ⁇ TBP At least one of Se-TPP, Se ⁇ ODE, Se ⁇ OA, Se ⁇ ODA, Se ⁇ TOA, Se ⁇ ODPA or Se ⁇ OLA.
  • the method for preparing a nano material wherein the anion precursor of the first compound and/or the second compound comprises a precursor of S, and the precursor of the S is S-TOP, S-TBP At least one of S-TPP, S-ODE, S-OA, S-ODA, S-TOA, S-ODPA, S-OLA or alkyl mercaptan.
  • the method for preparing a nano material wherein the anion precursor of the first compound and/or the second compound comprises a precursor of Te, and the precursor of the Te is Te ⁇ TOP, Te ⁇ TBP At least one of Te ⁇ TPP, Te ⁇ ODE, Te ⁇ OA, Te ⁇ ODA, Te ⁇ TOA, Te ⁇ ODPA, or Te ⁇ OLA.
  • the method for preparing the nano material wherein the heating temperature is between 100 ° C and 400 ° C.
  • the method for preparing the nano material wherein the heating time is between 2 s and 24 h.
  • the method for preparing a nano material wherein, in synthesizing the first compound, the molar ratio of the cationic precursor to the anionic precursor is between 100:1 and 1:50.
  • the method for preparing the nano material wherein, in synthesizing the second compound, the molar ratio of the cationic precursor to the anionic precursor is between 100:1 and 1:50.
  • a semiconductor device comprising the nanomaterial of any of the above.
  • the semiconductor device wherein the semiconductor device is any one of an electroluminescent device, a photoluminescence device, a solar cell, a display device, a photodetector, a bioprobe, and a nonlinear optical device.
  • the present invention provides a nano material having a fully graded alloy composition in a radial direction from the inside to the outside, which not only achieves more efficient luminous efficiency, but also satisfies the semiconductor device and corresponding display technology.
  • the comprehensive performance requirements of nanomaterials are an ideal nanomaterial suitable for semiconductor devices and display technologies.
  • 1 is a graph showing the energy level structure of a preferred embodiment of a nanomaterial of the present invention.
  • FIG. 2 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 13 of the present invention.
  • FIG. 3 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 14 of the present invention.
  • FIG. 4 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 15 of the present invention.
  • FIG. 5 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 16 of the present invention.
  • FIG. 6 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 17 of the present invention.
  • FIG. 7 is a schematic structural view of a quantum dot light emitting diode according to Embodiment 18 of the present invention.
  • the present invention provides a nano material, a preparation method, and a semiconductor device.
  • the present invention will be further described in detail below in order to make the objects, technical solutions and effects of the present invention more clear and clear. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
  • the invention provides a nano material, wherein the nano material comprises N nanostructure units arranged in a radial direction, wherein N ⁇ 2;
  • the nanostructure unit includes A1 and A2 types, and the A1 type is a uniform alloy composition structure having uniform energy level widths in a radial direction; the A2 type is a graded alloy having a wider outer energy level width in a radial direction Component structure;
  • the radial direction herein refers to the direction from the center of the nanomaterial, for example, assuming that the nanomaterial of the present invention is a spherical or spherical structure, then the radial direction refers to the direction of the radius, the nanomaterial
  • the center of the nano-material refers to the center of its physical structure, and the surface of the nano-material refers to the surface of its physical structure.
  • the interior of the nanomaterial consists of at least one layer of A1 type nanostructure unit, the exterior of which is composed of at least one layer of A2 type nanostructure unit;
  • the energy level width of the nanostructure unit near the center of the nano material is not greater than the energy level width of the nanostructure unit away from the center of the nano material, and the adjacent graded alloy composition structure
  • the energy level of the nanostructure unit is continuous; that is, when the outer portion of the luminescent material includes at least two layers of A2 type nanostructure units, the energy levels of the adjacent A2 type nanostructure units are continuous That is, the energy level width of the nanostructure unit of each adjacent graded alloy component structure in the present invention has a continuous change characteristic, rather than a mutated structure, that is, the external synthetic component of the nano material has continuity, and this characteristic It is more conducive to achieving high luminous efficiency.
  • the nanomaterial in the present invention belongs to a quantum well level structure, and its energy level structure is shown in FIG. That is, in the nanomaterial, the distribution of nanostructure units is A1...A1A2...A2, that is, the interior of the nanomaterial is composed of nanostructure units of type A1, and the outer portion of the nanomaterial is composed of A2 type nanostructure unit composition, and the number of A1 type nanostructure units and the number of A2 type nano structure units are greater than or equal to 1;
  • the energy level width is uniform; in the A2 type nanostructure unit, the energy level width is wider toward the outside; in the nanostructure unit adjacent in the radial direction, The energy level width of the nanostructure unit near the center is not greater than the energy level width of the nanostructure unit away from the center; and the energy level width of the adjacent nanostructure unit has a continuous structure.
  • the energy level structure of Figure 1 is referred to as a quantum well level structure in a particular embodiment.
  • the alloy nanostructure unit comprises Group II and Group VI elements, that is, the A1 type nanostructure unit is a uniform alloy component structure comprising Group II and Group VI elements; the A2 type nanostructure unit is included Graded alloy component structure of Group II and Group VI elements.
  • the Group II elements include, but are not limited to, Zn, Cd, Hg, Cn, and the like.
  • the Group VI elements include, but are not limited to, O, S, Se, Te, Po, Lv, and the like.
  • the alloy component of the A1 type nanostructure unit is Cd x0 Zn 1 ⁇ x0 Se y0 S 1 ⁇ y0 , where 0 ⁇ x0 ⁇ 1, 0 ⁇ y0 ⁇ 1, and x0 and y0 are not 0 at the same time. They are not at the same time, and x0 and y0 are fixed values in the corresponding structural unit of the A1 type.
  • the alloy composition at a certain point is Cd 0.5 Zn 0.5 Se 0.5 S 0.5
  • the alloy composition at another point should also be Cd 0.5 Zn 0.5 Se 0.5 S 0.5 .
  • the alloy composition of the A2 type nanostructure unit is Cd x1 Zn 1 -x1 Se y1 S 1 ⁇ y1 , where 0 ⁇ x1 ⁇ 1, 0 ⁇ y1 ⁇ 1, and x1 and y1 are not 0 at the same time. Not at the same time.
  • the alloy composition at a certain point is Cd 0.5 Zn 0.5 Se 0.5 S 0.5
  • the alloy composition at another point is Cd 0.3 Zn 0.7 Se 0.4 S 0.6 .
  • the alloy component of the point A is Cd x A Zn 1 ⁇ x A Se y A S 1 ⁇ y A
  • the alloy composition of the point B is Cd x B Zn 1 ⁇ x B Se y B S 1 ⁇ y B , where point A is closer to the center of the nanomaterial relative to point B, and the composition of points A and B satisfies: x A > x B , y A > y B .
  • the A2 type nanostructure unit a gradual structure is formed in the radial direction, and since the radial direction is outward (i.e., away from the center of the nanomaterial), the Cd and Se contents are lower, Zn and The higher the S content, the wider the energy level width will be based on the characteristics of these elements.
  • the nanostructure unit comprises a 2-20 layer of a single atomic layer. That is, each nanostructure unit contains 2-20 layers of monoatomic layers. Preferred are 2 monoatomic layers to 5 monoatomic layers. The preferred number of layers ensures that the quantum dots achieve good luminescence quantum yield and efficient charge injection efficiency.
  • each of the monoatomic layers of the A1 type and the A2 type nanostructure unit is a minimum structural unit, that is, a single atomic layer of each layer has a fixed alloy component, and two adjacent atomic layers are adjacent.
  • a graded alloy composition may be formed between the layers, for example, in the A2 type nanostructure unit, the monoatomic layer away from the center of the nanomaterial has a low Cd and Se content, a high Zn and S content, and a single near the center of the nanomaterial.
  • the atomic layer has a low Cd and Se content, and a high content of Zn and S, thereby forming a graded alloy component structure.
  • the monoatomic layer of each layer has the same alloy composition to form a uniform alloy composition structure.
  • the A1 type and the A2 type nanostructure unit each comprise a 1-10 layer of a cell layer, that is, each nanostructure unit comprises a 1-10 layer of a cell layer, for example, a cell layer comprising 2-5 layers.
  • the cell layer is the smallest structural unit, that is, the cell layer of each layer, the alloy composition of which is fixed, that is, the same lattice parameter and element in each cell layer.
  • Each of the nanostructure units is a closed unit cell curved surface formed by continuous connection of the unit cell layers.
  • a continuous alloy composition structure is formed between the two monoatomic layers at the interface of the nanostructure units adjacent to the graded alloy composition structure in the radial direction. That is, between the two monoatomic layers at the junction of the nanostructured units of the two graded alloy composition structures is a continuous alloy composition structure, that is, the energy level width is also gradual rather than abrupt.
  • a continuous alloy composition structure is formed between the two unit cell layers at the junction of the quantum dot structure unit of the graded alloy composition structure adjacent in the radial direction.
  • the nanostructured unit of the adjacent graded alloy composition structure mentioned above is adjacent A2 Type of nanostructure unit.
  • the nanomaterial of the present invention has a continuous alloy composition in the radial direction from the inside to the outside between adjacent A2 type nanostructure units.
  • the quantum dot structure has a characteristic that the composition has a continuous change from the inside to the outside in the radial direction.
  • the nanomaterial of the present invention is not only beneficial for achieving more efficient
  • the luminous efficiency is also more suitable for the comprehensive performance requirements of semiconductor devices and corresponding display technologies for nanomaterials. It is an ideal quantum dot nanomaterial suitable for semiconductor devices and display technologies.
  • the nano material of the above structure can achieve a luminescence quantum yield ranging from 1% to 100%, and a preferred luminescence quantum yield range of 30% to 100%, and the quantum dot can be ensured within a preferred luminescence quantum yield range. Good applicability.
  • the nano material of the above structure can realize the luminescence peak wavelength range of 400 nm to 700 nm, and the preferred luminescence peak wavelength range is 430 nm to 660 nm, and the preferred quantum dot luminescence peak wavelength range can ensure the nano material is here.
  • a luminescence quantum yield of greater than 30% is achieved in the range.
  • the half peak width of the luminescence peak of the nano material is from 12 nm to 80 nm.
  • the nanomaterial provided by the invention has the following beneficial effects: firstly, it helps to minimize the lattice tension between quantum dot crystals of different alloy compositions and alleviate lattice mismatch, thereby reducing the formation of interface defects.
  • the luminous efficiency of quantum dots is improved.
  • the energy level structure formed by the nano material provided by the invention is more favorable for the effective binding of the electron cloud in the quantum dot, greatly reducing the probability of diffusion of the surface of the electron cloud vector sub-point, thereby greatly suppressing the quantum dot non-radiation.
  • the Auger recombination loss of the transition reduces the quantum dot flicker and improves the luminous efficiency of the quantum dots.
  • the energy level structure formed by the nano material provided by the invention is more favorable for improving the injection efficiency and transmission efficiency of the quantum dot light-emitting layer charge in the semiconductor device; at the same time, the charge accumulation and the resulting exciton quenching can be effectively avoided.
  • the easily controllable multi-level structure formed by the quantum dot material provided by the present invention can fully satisfy and match the energy level structure of other functional layers in the device, so as to achieve matching of the overall energy level structure of the device, thereby contributing to Achieve efficient semiconductor devices.
  • a method for preparing a nanomaterial as described above comprising the steps of:
  • a cation exchange reaction occurs between the first compound and the second compound to form a nanomaterial, and the wavelength of the luminescence peak of the nanomaterial is unchanged first, followed by a blue shift.
  • the preparation method of the invention combines the quantum dot SILAR synthesis method with the quantum dot one-step synthesis method to generate nano materials, in particular, the use of quantum dot layer-by-layer growth and the use of quantum dot one-step synthesis method to form a graded component transition shell. That is, two thin layers of a compound having the same or different alloy compositions are successively formed at predetermined positions, and the alloy component distribution at a predetermined position is achieved by causing a cation exchange reaction between the two layers of compounds. Repeating the above process can continuously achieve the distribution of the alloy composition at a predetermined position in the radial direction.
  • the first compound and the second compound may be binary or binary compounds.
  • the wavelength of the luminescence peak of the nano material first changes and then shifts blue. If the wavelength of the luminescence peak does not change, the width of the energy level is constant. If the blue shift occurs, the luminescence peak shifts toward the short wave direction, that is, the width of the energy level is widened. As shown in FIG. 1, in the radial direction of the quantum dot, the energy level width is constant in the first interval, and the energy level width is widened (blue shift) in the second interval.
  • the cation precursor of the first compound and/or the second compound includes: a precursor of Zn, and the precursor of the Zn is dimethyl Zinc, diethyl zinc (diethyl Zinc) , Zinc acetate, Zinc acetylacetonate, Zinc iodide, Zinc bromide, Zinc chloride, Zinc fluoride, Zinc carbonate (Zinc carbonate), Zinc cyanide, Zinc nitrate, Zinc oxide, Zinc peroxide, Zinc perchlorate, Zinc sulfate At least one of Zinc oleate or Zinc stearate, etc., but is not limited thereto.
  • the cationic precursor of the first compound and/or the second compound includes Cd
  • the precursor, the precursor of the Cd is dimethyl cadmium, diethyl cadmium, cadmium acetate, cadmium acetylacetonate, cadmium iodide Cadmium bromide, cadmium chloride, cadmium fluoride, cadmium carbonate, cadmium nitrate, cadmium oxide, cadmium perchlorate At least one of (cadmium perchlorate), cadmium phosphide, cadmium sulfate, cadmium oleate, or cadmium stearate, but is not limited thereto.
  • the anion precursor of the first compound and/or the second compound includes a precursor of Se, such as a compound formed by any combination of Se and some organic substances, specifically Se ⁇ TOP (selenium ⁇ trioctylphosphine), Se ⁇ TBP (selenium-tributylphosphine), Se ⁇ TPP (selenium ⁇ triphenylphosphine), Se ⁇ ODE (selenium ⁇ 1 ⁇ octadecene), Se ⁇ OA (selenium ⁇ oleic acid), Se ⁇ ODA (selenium ⁇ octadecylamine), Se ⁇ TOA ( At least one of selenium-trioctylamine), Se ⁇ ODPA (selenium ⁇ octadecylphosphonic acid) or Se ⁇ OLA (selenium ⁇ oleylamine), and the like, but is not limited thereto.
  • Se ⁇ TOP senium ⁇ trioctylphosphine
  • Se ⁇ TBP senium-tribut
  • the anion precursor of the first compound and/or the second compound includes a precursor of S, such as a compound formed by any combination of S and some organic substances, specifically S-TOP (sulfur-trioctylphosphine), S ⁇ TBP(sulfur-tributylphosphine), S ⁇ TPP(sulfur ⁇ triphenylphosphine), S ⁇ ODE(sulfur ⁇ 1 ⁇ octadecene), S ⁇ OA(sulfur ⁇ oleic acid), S ⁇ ODA(sulfur ⁇ octadecylamine), S ⁇ TOA (sulfur-trioctylamine), S-ODPA (sulfur-octadecylphosphonic acid) or S-OLA (sulfur-oleylamine), etc., but is not limited thereto; the precursor of S may also be an alkyl thiol, The alkyl mercaptan may be hexanethiol, octanethio
  • the anionic precursor of the first compound and/or the second compound comprises Te a precursor, the precursor of Te is at least one of Te ⁇ TOP, Te ⁇ TBP, Te ⁇ TPP, Te ⁇ ODE, Te ⁇ OA, Te ⁇ ODA, Te ⁇ TOA, Te ⁇ ODPA or Te ⁇ OLA .
  • the above cationic precursor and anionic precursor may be determined according to the final nanomaterial composition to determine one or more of them: for example, when a nanomaterial of CdxZn1 ⁇ xSeyS1 ⁇ y needs to be synthesized, a precursor of Cd and a precursor of Zn are required.
  • the precursor of Se the precursor of S; if it is necessary to synthesize a nanomaterial of CdxZn1-xS, a precursor of Cd, a precursor of Zn, a precursor of S, and a nanomaterial of CdxZn1-xSe are required.
  • a precursor of Cd, a precursor of Zn, and a precursor of Se are required.
  • the conditions under which the cation exchange reaction takes place are preferably carried out by heating, for example, a heating temperature of between 100 ° C and 400 ° C, and a preferred heating temperature of between 150 ° C and 380 ° C.
  • the heating time is between 2 s and 24 h, and the preferred heating time is between 5 min and 4 h.
  • the thickness range and extent of cation exchange directly determines the distribution of the graded alloy composition formed.
  • the distribution of the graded alloy components formed by the cation exchange is also determined by the thickness of the binary or multicomponent compound nanomaterials formed by each.
  • the molar ratio of the cationic precursor to the anionic precursor is from 100:1 to 1:50 (specifically, the molar ratio of the cation to the anion), for example, when the first layer of the compound is formed, the cationic precursor
  • the molar ratio of the anion precursor is from 100:1 to 1:50; in forming the second layer compound, the molar ratio of the cationic precursor to the anionic precursor is from 100:1 to 1:50, and the preferred ratio is 20:1 to 1:10, the preferred molar ratio of cationic precursor to anionic precursor ensures that the reaction rate is within an easily controllable range.
  • the nanomaterial prepared by the above preparation method has a luminescence peak wavelength ranging from 400 nm to 700 nm, and a preferred luminescence peak wavelength range is from 430 nm to 660 nm, and a preferred quantum
  • the point luminescence peak wavelength range ensures that quantum dots achieve a luminescence quantum yield of greater than 30% in this range.
  • the nanomaterial prepared by the above preparation method has a luminescence quantum yield ranging from 1% to 100%, and the preferred luminescence quantum yield ranges from 30% to 100%, and the preferred luminescent quantum yield range can ensure good application of quantum dots. Sex.
  • the present invention provides another preparation method of the nano material as described above, which comprises the steps of:
  • the difference between this method and the former method is that the former one forms two layers of compounds one after another, and then a cation exchange reaction occurs to realize the distribution of the graded alloy composition, and the latter method directly controls the addition at a predetermined position.
  • the cationic precursor and the anionic precursor of the alloy component are synthesized and reacted to form a nanomaterial, thereby realizing the distribution of the graded alloy component of the present invention.
  • the reaction principle is that the highly reactive cationic precursor and the anionic precursor react first, the reactive precursor with low reactivity and the anionic precursor react, and during the reaction, different cations undergo cations. The reaction is exchanged to achieve the distribution of the graded alloy composition of the present invention.
  • reaction temperature, the reaction time, the ratio, and the like may vary depending on the specific nanomaterials to be synthesized, and are substantially the same as the former method described above, and will be described later in the specific examples.
  • the present invention also provides a semiconductor device comprising the nanomaterial of any of the above.
  • the semiconductor device is any one of an electroluminescent device, a photoluminescence device, a solar cell, a display device, a photodetector, a bioprobe, and a nonlinear optical device.
  • the amount of the nanomaterial of the present invention as a material of the luminescent layer is used.
  • Sub-point electroluminescent device Such quantum dot electroluminescent devices are capable of achieving: 1) high efficiency charge injection, 2) high luminance, 3) low drive voltage, 4) high device efficiency and the like.
  • the nano material of the invention has the characteristics of easy control and multi-level structure, and can fully satisfy and match the energy level structure of other functional layers in the device, so as to achieve matching of the overall energy level structure of the device, thereby contributing to A highly efficient and stable semiconductor device is realized.
  • the photoluminescent device refers to a device that relies on an external light source to obtain energy, thereby generating excitation and causing light emission, and ultraviolet radiation, visible light, and infrared radiation can cause photoluminescence, such as phosphorescence and fluorescence.
  • the nanomaterial of the present invention can be used as a light-emitting material of a photoluminescent device.
  • the solar cell is also called a photovoltaic device, and the nano material of the invention can be used as a light absorbing material of a solar cell, thereby effectively improving various performances of the photovoltaic device.
  • the display device refers to a backlight module or a display panel to which the backlight module is applied, and the display panel can be applied to various products, such as a display, a tablet, a mobile phone, a notebook computer, a flat-panel TV, and a wearable display. Equipment or other products that contain different sized display panels.
  • the photodetector refers to a device capable of converting an optical signal into an electrical signal.
  • the principle is that the conductivity of the irradiated material is changed by radiation, and the quantum dot material is applied to the photodetector, which has the following advantages: normal incidence Light sensitivity, high photoconductivity, high detection rate, continuous detection wavelength and low temperature preparation.
  • the photogenerated electron-hole pairs generated by the quantum dot photosensitive layer ie, using the nanomaterial of the present invention
  • the structured photodetector has a lower drive voltage and can operate with low applied bias or even 0 applied bias and is easy to control.
  • the bioprobe refers to a device that modifies a certain type of material to have a labeling function, for example, coating the nano material of the present invention to form a fluorescent probe, which is used in the field of cell imaging or substance detection, as opposed to
  • the traditional organic fluorescent dye probe adopts the biological probe prepared by the nano material of the invention, and has the characteristics of high fluorescence intensity, good chemical stability and strong anti-photobleaching ability, and has wide application.
  • the nonlinear optical device belongs to the field of optical laser technology and is widely used, for example, for electricity.
  • Light-on and laser modulation for laser frequency conversion, laser frequency tuning; optical information processing, improved image quality and beam quality; as a nonlinear etalon and bistable device; study of high-excited states and high resolution of matter The spectrum and the internal energy and excitation transfer processes of the material as well as other relaxation processes.
  • a precursor of a cationic Cd, a precursor of a cationic Zn, a precursor of an anion Se, and a precursor of an anion S are injected into a reaction system to form a Cd y Zn 1 ⁇ y Se b S 1 ⁇ b layer (where 0 ⁇ y) ⁇ 1,0 ⁇ b ⁇ 1); the precursor of the cationic Cd, the precursor of the cationic Zn, the precursor of the anion Se, and the precursor of the anion S are continuously injected into the reaction system, in the above Cd y Zn 1 ⁇ y Se b
  • the surface of the S 1 - b layer forms a layer of Cd z Zn 1 ⁇ z Se c S 1 ⁇ c (where 0 ⁇ z ⁇ 1, and z is not equal to y, 0 ⁇ c ⁇ 1); at a certain heating temperature and heating time Under the same reaction conditions, the exchange of Cd and Zn ions in the inner and outer nanocrystals (ie, the above two layers of compounds) occurs;
  • Example 2 Preparation based on CdZnS/CdZnS quantum dots
  • the precursor of the cationic Cd, the precursor of the cationic Zn, and the precursor of the anion S are injected into the reaction system to form a Cd y Zn 1 -y S layer (where 0 ⁇ y ⁇ 1 ); the precursor of the cationic Cd is continued.
  • the precursor of the bulk, cationic Zn and the precursor of the anion S are injected into the reaction system to form a Cd z Zn 1 ⁇ z S layer on the surface of the above Cd y Zn 1 ⁇ y S layer (where 0 ⁇ z ⁇ 1, and z Not equal to y); under certain reaction conditions such as heating temperature and heating time, the exchange of Cd and Zn ions in the inner and outer nanocrystals (ie, the above two layers of compounds) occurs; due to the limited migration distance of the cations and the further migration The smaller the probability of migration, the gradient alloy composition distribution of Cd content and Zn content near the interface between Cd y Zn 1 ⁇ y S layer and Cd z Zn 1 ⁇ z S layer, ie Cd x Zn 1 ⁇ x S, where 0 ⁇ x ⁇ 1.
  • the precursor of the cationic Cd, the precursor of the cationic Zn, and the precursor of the anion Se are injected into the reaction system to form a layer of Cd y Zn 1 ⁇ y Se (where 0 ⁇ y ⁇ 1 ); the precursor of the cation Cd is continued.
  • the precursor of the cationic Zn and the precursor of the anion Se are injected into the reaction system to form a Cd z Zn 1 ⁇ z Se layer on the surface of the above Cd y Zn 1 ⁇ y Se layer (where 0 ⁇ z ⁇ 1, and z does not Equivalent to y); under certain reaction conditions such as heating temperature and heating time, the exchange of Cd and Zn ions in the inner and outer nanocrystals occurs; the probability of migration due to the limited migration distance of the cation and the farther migration distance is smaller.
  • a graded alloy composition distribution of Cd content and Zn content is formed near the interface between the Cd y Zn 1 ⁇ y Se layer and the Cd z Zn 1 ⁇ z Se layer, that is, Cd x Zn 1 ⁇ x Se, where 0 ⁇ x ⁇ 1.
  • the precursor of the cationic Cd and the precursor of the anion S are injected into the reaction system to form a CdS layer; the precursor of the cationic Zn and the precursor of the anion S are continuously injected into the reaction system to form on the surface of the CdS layer.
  • ZnS layer under certain reaction conditions such as heating temperature and heating time, the Zn cation of the outer layer will gradually migrate to the inner layer and undergo cation exchange reaction with Cd cation, that is, Cd ion migrates to the outer layer, and Cd and Zn occur.
  • the precursor of the cationic Cd and the precursor of the anion Se are first injected into the reaction system to form a CdSe layer; the precursor of the cationic Zn and the precursor of the anion Se are continuously injected into the reaction system to form ZnSe on the surface of the CdSe layer.
  • the Zn cation of the outer layer gradually migrates to the inner layer and undergoes cation exchange reaction with Cd cations, that is, Cd ions migrate to the outer layer, and Cd and Zn ions occur.
  • the interchangeability of the cations due to the limited migration distance of the cations and the migration distance of the migration distance is smaller.
  • the Cd content near the interface between the CdSe layer and the ZnSe layer gradually decreases along the radial direction, and the Zn content decreases.
  • the distribution of the graded alloy composition gradually increasing radially outward that is, Cd x Zn 1 - x Se, where 0 ⁇ x ⁇ 1 and x is monotonously decreasing from 1 to 0 from the inside to the outside (radial direction).
  • the precursor of the cationic Cd, the precursor of the anion Se, and the precursor of the anion S are injected into the reaction system to form a CdSe b S 1 -b layer (where 0 ⁇ b ⁇ 1); the precursor of the cationic Zn is continued,
  • the precursor of the anion Se and the precursor of the anion S are injected into the reaction system to form a layer of ZnSe c S 1 -c on the surface of the above CdSe b S 1 -b layer (where 0 ⁇ c ⁇ 1); at a certain heating temperature
  • the Zn cation of the outer layer gradually migrates to the inner layer and undergoes cation exchange reaction with the Cd cation, that is, the Cd ion migrates to the outer layer, and the exchange of Cd and Zn ions occurs;
  • the migration distance is limited and the migration distance of the migration distance is smaller.
  • the Cd content in the vicinity of the interface between the CdSe b S 1 ⁇ b layer and the ZnSe c S 1 ⁇ c layer gradually decreases along the radial direction.
  • Example 7 Preparation based on ZnS/CdS quantum dots
  • the precursor of the cationic Zn and the precursor of the anion S are first injected into the reaction system to form a ZnS layer; the precursor of the cationic Cd and the precursor of the anion S are continuously injected into the reaction system to form a CdS on the surface of the ZnS layer.
  • the Cd cation of the outer layer gradually migrates to the inner layer and undergoes cation exchange reaction with the Zn cation, that is, Zn ions migrate to the outer layer, and Cd and Zn ions occur.
  • Example 8 Preparation based on ZnSe/CdSe quantum dots
  • a precursor of a cationic Zn and a precursor of an anion Se are injected into the reaction system to form a ZnSe layer; and a precursor of a cationic Cd and a precursor of an anion Se are continuously injected into the reaction system to form a CdSe on the surface of the ZnSe layer.
  • the Cd cation of the outer layer gradually migrates to the inner layer and undergoes cation exchange reaction with the Zn cation, that is, Zn ions migrate to the outer layer, and Cd and Zn ions occur.
  • the interchangeability of the cations due to the limited migration distance of the cations and the migration distance of the migration distance is smaller.
  • the Zn content near the interface between the ZnSe layer and the CdSe layer gradually decreases along the radial direction, and the Cd content decreases.
  • a precursor of a cationic Zn, a precursor of an anion Se, and a precursor of an anion S are first injected into a reaction system to form a ZnSe b S 1 -b layer (where 0 ⁇ b ⁇ 1); the precursor of the cationic Cd is continued, The precursor of the anion Se and the precursor of the anion S are injected into the reaction system to form a layer of CdSe c S 1-c on the surface of the above ZnSebS1 ⁇ b layer (where 0 ⁇ c ⁇ 1); at a certain heating temperature and heating time Under the same reaction conditions, the Cd cation of the outer layer will gradually migrate to the inner layer and undergo cation exchange reaction with the Zn cation, that is, the Zn ion migrates to the outer layer, and the exchange of Cd and Zn ions occurs; the migration distance of the cation is limited.
  • the Zn content in the vicinity of the interface between the ZnSe b S 1 ⁇ b layer and the CdSe c S 1 ⁇ c layer will gradually decrease along the radial direction, and the Cd content will decrease.
  • cadmium oleate first precursor 1 mmol of cadmium oxide (CdO), 1 mL of oleic acid (Oleic acid) and 5 mL of octadecene (1 -Octadecene) were placed in a 100 mL three-necked flask and vacuum degassed at 80 ° C for 60 mins. . It is then switched to a nitrogen atmosphere and stored at this temperature for use.
  • CdO cadmium oxide
  • Oleic acid oleic acid
  • octadecene 1 -Octadecene
  • cadmium oleate second precursor 0.6 mmol of cadmium oxide (CdO), 0.6 mL of oleic acid (Oleic acid) and 5.4 mL of octadecene (1 -Octadecene) were placed in a 100 mL three-necked flask under nitrogen The mixture was heated under reflux at 250 ° C for 120 mins to obtain a transparent second precursor of cadmium oleate.
  • CdO cadmium oxide
  • Oleic acid oleic acid
  • octadecene octadecene
  • the first precursor of cadmium oleate was heated to 310 ° C under nitrogen atmosphere, and the thiooctadecene precursor was rapidly injected into the reaction system to rapidly form CdS. After 10 mins of reaction, the zinc oleate precursor was completely injected into the reaction system. Subsequently, 3 mL of the trioctylphosphine sulfide precursor and 6 mL of the cadmium oleate precursor were simultaneously injected into the reaction system at a rate of 3 mL/h and 10 mL/h, respectively.
  • cadmium oleate precursor 0.4 mmol of cadmium oxide (CdO), 1 mL of oleic acid (Oleic acid) and 5 mL of octadecene (1 -Octadecene) were placed in a 100 mL three-necked flask and vacuum degassed at 80 ° C for 60 mins. It was then heated to reflux at 250 ° C under a nitrogen atmosphere and stored at this temperature for use.
  • CdO cadmium oxide
  • Oleic acid oleic acid
  • octadecene 1 -Octadecene
  • the cadmium oleate precursor was heated to 310 ° C under nitrogen atmosphere, and the trioctylphosphine precursor was quickly injected into the reaction system to rapidly form CdSe. After 5 mins, all the zinc oleate precursors were injected into the reaction. In the system, 2 mL of a trioctylphosphine selenide-trioctylphosphine sulfide precursor was added dropwise to the reaction system at a rate of 2 mL/h until the precursor was injected.
  • the product was repeatedly dissolved and precipitated with toluene and anhydrous methanol, and purified by centrifugation to obtain a green fluorescent quantum dot having a quantum well level structure.
  • cadmium oleate precursor 0.8 mmol of cadmium oxide (CdO), 4 mL of oleic acid (Oleic acid) and 10 mL of octadecene (1 -Octadecene) were placed in a 100 mL three-necked flask and vacuum degassed at 80 ° C for 60 mins. It was then heated to reflux at 250 ° C under a nitrogen atmosphere and stored at this temperature for use.
  • CdO cadmium oxide
  • Oleic acid oleic acid
  • octadecene 1 -Octadecene
  • Zinc oleate precursor preparation 12mmol zinc acetate [Zn(acet) 2 ], 10mL oleic acid (Oleic acid) and 10mL octadecene (1 ⁇ Octadecene) were placed in a 100mL three-necked flask and vacuum degassed at 80 ° C 60mins.
  • the cadmium oleate precursor was heated to 310 ° C under nitrogen atmosphere, and the trioctylphosphine precursor was quickly injected into the reaction system to rapidly form CdSe. After 10 mins of reaction, the zinc oleate precursor was injected into the reaction. In the system, 2 mL of a trioctylphosphine selenide-trioctylphosphine sulfide precursor was added dropwise to the reaction system at a rate of 4 mL/h. After the reaction is completed, the reaction solution is cooled to room temperature. Thereafter, the product was repeatedly dissolved and precipitated with toluene and anhydrous methanol, and purified by centrifugation to obtain a red fluorescent quantum dot having a quantum well level structure.
  • the quantum dot light-emitting diode of this embodiment comprises, in order from bottom to top, an ITO substrate 11, a bottom electrode 12, a PEDOT: PSS hole injection layer 13, a poly-TPD hole transport layer 14, and a quantum dot.
  • the light-emitting layer 15, the ZnO electron transport layer 16, and the Al top electrode 17.
  • a quantum dot light-emitting layer is prepared on the poly-TPD hole transport layer 14. 15. The thickness was 20 nm, and then a 40 nm ZnO electron transport layer 16 and a 100 nm Al top electrode 17 were prepared on the quantum dot light-emitting layer 15.
  • the nanomaterial of the quantum dot luminescent layer 15 is the nanomaterial as described in Example 10.
  • the quantum dot light emitting diode in this embodiment includes, in order from bottom to top, an ITO substrate 21, a bottom electrode 22, a PEDOT: PSS hole injection layer 23, and a poly(9-vinylcarbazole) (PVK) space.
  • a quantum dot light-emitting layer 25 is prepared on the PVK hole transport layer 24, and the thickness is At 20 nm, a 40 nm ZnO electron transport layer 26 and a 100 nm Al top electrode 27 were subsequently prepared on the quantum dot light-emitting layer 25.
  • the nanomaterial of the quantum dot luminescent layer 25 is the nanomaterial as described in Example 11.
  • the quantum dot light emitting diode of this embodiment includes, in order from bottom to top, an ITO substrate 31, a bottom electrode 32, a PEDOT: PSS hole injection layer 33, a poly-TPD hole transport layer 34, and a quantum dot.
  • a quantum dot light-emitting layer is prepared on the poly-TPD hole transport layer 34.
  • 35, a thickness of 20 nm, and then a 30 nm TPBi electron transport layer 36 and a 100 nm Al top electrode 37 were prepared by vacuum evaporation on the quantum dot light-emitting layer 35.
  • the nanomaterial of the quantum dot luminescent layer 35 is the nanomaterial as described in Example 12.
  • the quantum dot light-emitting diode of this embodiment comprises, in order from bottom to top, an ITO substrate 41, a bottom electrode 42, a ZnO electron transport layer 43, a quantum dot light-emitting layer 44, an NPB hole transport layer 45, and a MoO. 3 hole injection layer 46 and Al top electrode 47.
  • a bottom electrode 42 and a 40 nm ZnO electron transport layer 43 are sequentially prepared on the ITO substrate 41, and a quantum dot light-emitting layer 44 is formed on the ZnO electron transport layer 43 to a thickness of 20 nm, and then a 30 nm NPB space is prepared by a vacuum evaporation method.
  • the nanomaterial of the quantum dot luminescent layer 44 is the nanomaterial as described in Example 10.
  • the quantum dot light emitting diode of this embodiment includes, in order from bottom to top, a glass substrate 51, an Al electrode 52, a PEDOT: PSS hole injection layer 53, a poly-TPD hole transport layer 54, and a quantum dot.
  • a 100 nm Al electrode 52 was prepared on the glass substrate 51 by a vacuum evaporation method, and then a 30 nm PEDOT:PSS hole injection layer 53 and a 30 nm poly-TPD hole transport layer 54 were sequentially prepared, followed by a poly-TPD hole transport layer 54.
  • a quantum dot light-emitting layer 55 was prepared to have a thickness of 20 nm, and then a 40 nm ZnO electron transport layer 56 was prepared on the quantum dot light-emitting layer 55. Finally, 120 nm of ITO was prepared as a top electrode 57 by a sputtering method.
  • the nano-material of the quantum dot luminescent layer 55 is as The nanomaterial described in Example 11.
  • the quantum dot light emitting diode of the present embodiment includes a glass substrate 61, an Al electrode 62, a ZnO electron transport layer 63, a quantum dot light emitting layer 64, an NPB hole transport layer 65, and a MoO. 3 hole injection layer 66 and ITO top electrode 67.
  • a 100 nm Al electrode 62 is prepared on the glass substrate 61 by a vacuum evaporation method, and then a 40 nm ZnO electron transport layer 63, a 20 nm quantum dot light emitting layer 64 is sequentially prepared, and then a 30 nm NPB hole transport layer 65 is prepared by a vacuum evaporation method. 5 nm MoO 3 hole injection layer 66, and finally 120 nm ITO was prepared as a top electrode 67 by a sputtering method.
  • the nanomaterial of the quantum dot luminescent layer is the nanomaterial as described in Example 12.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Nanotechnology (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Luminescent Compositions (AREA)

Abstract

一种纳米材料、制备方法及半导体器件，其中，所述纳米材料包括N个在径向方向上依次排布的纳米结构单元，其中N≥2；所述纳米结构单元包括A1和A2类型，所述A1类型为径向方向上能级宽度一致的均一组分结构；所述A2类型为径向方向上越向外能级宽度越宽的渐变合金组分结构；所述纳米材料的内部由至少一层A1类型的纳米结构单元组成，所述纳米材料的外部由至少一层A2类型的纳米结构单元组成；在径向方向上相邻的纳米结构单元中，靠近纳米材料中心的纳米结构单元的能级宽度不大于远离纳米材料中心的纳米结构单元的能级宽度，且相邻的渐变合金组分结构的纳米结构单元的能级是连续的。

Description

一种纳米材料、制备方法及半导体器件 技术领域
本发明涉及量子点领域，尤其涉及一种纳米材料、制备方法及半导体器件。
背景技术
量子点是一种在三个维度尺寸上均被限制在纳米数量级的特殊材料，这种显著的量子限域效应使得量子点具有了诸多独特的纳米性质：发射波长连续可调、发光波长窄、吸收光谱宽、发光强度高、荧光寿命长以及生物相容性好等。这些特点使得量子点在平板显示、固态照明、光伏太阳能、生物标记等领域均具有广泛的应用前景。尤其是在平板显示应用方面，基于量子点材料的量子点电致发光二极管器件(Quantum dot light‐emitting diodes，QLED)借助于量子点纳米材料的特性和优化，已经在显示画质、器件性能、制造成本等方面展现出了巨大的潜力。虽然近年来QLED器件在各方面的性能不断得到提升，但无论是在器件效率还是在器件工作稳定性等基本器件性能参数上还与产业化应用的要求有相当的差距，这也大大阻碍了量子点电致发光显示技术的发展和应用。另外，不仅限于QLED器件，在其他领域中，量子点材料相对于传统材料的特性也被逐渐重视，例如光致发光器件、太阳能电池、显示器件、光电探测器、生物探针以及非线性光学器件等等，以下仅以QLED器件为例进行说明。
虽然量子点作为一种经典的纳米材料已经被研究和开发超过30年，但是利用量子点的优良发光特性并将其作为纳米材料应用在QLED器件及相应的显示技术中的研究时间还很短；因此目前绝大部分的QLED器件的开发 和研究均是基于已有经典结构体系的量子点材料，相应的量子点材料的筛选和优化的标准还基本是从量子点自身的发光性能例如量子点的发光峰宽、溶液量子产率等出发。将以上量子点直接应用于QLED器件结构中从而获得相应的器件性能结果。
但QLED器件及相应的显示技术作为一套复杂的光电器件体系，有诸多方面的因素会影响器件的性能。单从作为核心发光层材料的量子点材料出发，所需权衡的量子点性能指标就会复杂得多。
首先，量子点在QLED器件中是以量子点发光层固态薄膜的形式存在的，因此量子点材料原本在溶液中所得到的各项发光性能参数在形成固态薄膜后会表现出明显的差异：例如在固态薄膜中发光峰波长会有不同程度的红移(向长波长移动)、发光峰宽度会变大、量子产率会有不同程度的降低，也就是说量子点材料在溶液中的优良发光性能并不能完全被继承至QLED器件的量子点固态薄膜中。因此在设计和优化量子点材料的结构和合成配方时，需同时考虑量子点材料自身的发光性能最优化以及量子点材料在固态薄膜状态下的发光性能继承最大化。
其次，在QLED器件中量子点材料的发光是通过电致激发来实现的，即分别从QLED器件的阳极和阴极通电注入空穴和电子，空穴和电子通过QLED器件中相应功能层的传输在量子点发光层复合后，通过辐射跃迁的方式发射光子即实现发光。从以上过程可以看出，量子点自身的发光性能例如发光效率只是影响上述过程中辐射跃迁的效率，而QLED器件的整体发光效率还会同时受到上述过程中空穴和电子在量子点材料中的电荷注入和传输效率、空穴和电子在量子点材料中的相对电荷平衡、空穴和电子在量子点材料中的复合区域等的影响。因此在设计和优化量子点材料的结构尤其是量子点的精细核壳纳米结构时，还需重点考虑量子点形成固态薄膜以后的电学性能：例如量子点的电荷注入和传导性能、量子点的精细能带结构、量子点的激子寿命等。
最后，考虑到QLED器件及相应显示技术未来将通过极具生产成本优势的溶液法例如喷墨打印法进行制备，因此量子点的材料设计和开发需要考虑量子点溶液的加工性能，例如量子点溶液或打印墨水的可分散溶解性、胶体稳定性、打印成膜性等。同时，量子点材料的开发还要与QLED器件其他功能层材料以及器件的整体制备工艺流程和要求作协同。
总之，传统的仅从提升量子点自身发光性能考虑出发的量子点结构设计是无法满足QLED器件及相应显示技术对于量子点材料在光学性能、电学性能、加工性能等多方面的综合要求的。需要针对QLED器件及相应显示技术的要求，对量子点纳米材料的精细核壳结构、组分、能级等进行量身定制。
由于量子点的高表面原子比率，未与表面配体(Ligand)形成非共价键(Dangling bond)的原子将以表面缺陷态存在，这种表面缺陷态将会引起非辐射途径的跃迁从而使得量子点的发光量子产率大幅被降低。为解决这一问题，可以在原量子点外层表面生长包含另一种半导体材料的半导体壳层，形成量子点的核壳(core‐shell)结构，可以显著改善量子点的发光性能，同时增加量子点的稳定性。
可应用于高性能QLED器件开发的量子点材料主要为核壳结构的量子点，其核和壳成分分别固定且核壳具有明确边界，例如具有CdSe/ZnS核壳结构的量子点(J.Phys.Chem.,1996,100(2),468–471)、具有CdSe/CdS核壳结构的量子点(J.Am.Chem.Soc.1997,119,(30),7019‐7029)、具有CdS/ZnS核壳结构的量子点、具有CdS/CdSe/CdS核+多层壳层结构的量子点(Patent US 7,919,012 B2)、具有CdSe/CdS/ZnS核+多层壳层结构的量子点(J.Phys.Chem.B,2004,108(49),18826–18831)等。在这些核壳结构的量子点中，通常来说核和壳的组成成分是固定并且不同的，且一般是由一种阳离子和一种阴离子组成的二元化合物体系。在这种结构中，由于核和壳的生长是独立分别进行的，因此核和壳之间的边界是明确，即核和壳可以区分的。这 种核壳结构量子点的开发提升了原先单一成分量子点的发光量子效率、单分散性以及量子点稳定性。
以上所述核壳结构的量子点虽然部分提高了量子点性能，但无论从设计思路还是从优化方案上均还是基于提升量子点自身的发光效率方面考虑，其发光性能还有待提高，另外也未综合考虑半导体器件对于量子点材料的其他方面特殊要求。
因此，上述技术还有待于改进和发展。
发明内容
鉴于上述现有技术的不足，本发明的目的在于提供一种纳米材料、制备方法及半导体器件，旨在解决现有的纳米材料其发光性能有待提高、无法满足半导体器件对于纳米材料的要求的问题。
本发明的技术方案如下：
一种纳米材料，其中，所述纳米材料包括N个在径向方向上依次排布的纳米结构单元，其中N≥2；
所述纳米结构单元包括A1和A2类型，所述A1类型为径向方向上能级宽度一致的均一组分结构；所述A2类型为径向方向上越向外能级宽度越宽的渐变合金组分结构；
所述纳米材料的内部由至少一层A1类型的纳米结构单元组成，所述纳米材料的外部由至少一层A2类型的纳米结构单元组成；
在径向方向上相邻的纳米结构单元中，靠近纳米材料中心的纳米结构单元的能级宽度不大于远离纳米材料中心的纳米结构单元的能级宽度，且相邻的渐变合金组分结构的纳米结构单元的能级是连续的。
所述的纳米材料，其中，所述A1类型的量子点结构单元为包含II族和VI族元素的均一合金组分结构，所述A2类型的量子点结构单元为包含II族和VI族元素的渐变合金组分结构。需说明的是上述情况是优选情况，对 于渐变合金组分结构的量子点结构单元而言，其组分均为合金组分；而对于均一组分结构的量子点结构单元而言，其组分可以是合金组分，也可以是合金组分，但本发明优选的是合金组分，即所述均一组分结构为均一合金组分结构，更优选的是，包含II族和VI族元素，本发明后续实施例均以均一合金组分结构为例进行说明，但显然，对于非合金的均一组分结构同样可以实施。
所述的纳米材料，其中，所述A1类型的纳米结构单元的合金组分为Cdx0Zn1‐x0Sey0S1‐y0，其中0≤x0≤1，0≤y0≤1，并且x0和y0不同时为0和不同时为1，且x0和y0在相应A1类型的纳米结构单元内为固定值。
所述的纳米材料，其中，所述A2类型的纳米结构单元的合金组分组成为Cdx1Zn1‐x1Sey1S1‐y1，其中0≤x1≤1，0≤y1≤1，并且x1和y1不同时为0和不同时为1。
所述的纳米材料，其中，所述A2类型的纳米结构单元中，A点的合金组分分别为Cdx AZn1‐x ASey AS1‐y A，B点的合金组分为Cdx BZn1‐x BSey BS1‐y B，其中A点相对于B点更靠近纳米材料中心，且A点和B点的组成满足：x A>x B，y A>y B。
所述的纳米材料，其中，所述纳米结构单元包含2‐20层的单原子层，或者所述纳米结构单元包含1‐10层的晶胞层。
所述的纳米材料，其中，在径向方向上相邻的纳米结构单元交界处的两个单原子层之间形成连续合金组分结构，或者在径向方向上相邻的纳米结构单元交界处的两个晶胞层之间形成连续合金组分结构。
所述的纳米材料，其中，所述纳米材料的发光峰波长范围为400纳米至700纳米。
所述的纳米材料，其中，所述纳米材料的发光峰的半高峰宽为12纳米至80纳米。
一种如上所述的纳米材料的制备方法，其中，包括步骤：
在预定位置处合成第一种化合物；
在第一种化合物的表面合成第二种化合物，所述第一种化合物与所述第二种化合物的合金组分相同或者不同；
使第一种化合物和第二种化合物体之间发生阳离子交换反应形成纳米材料，所述纳米材料的发光峰波长先不变，而后出现蓝移。
所述的纳米材料的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Zn的前驱体，所述Zn的前驱体为二甲基锌、二乙基锌、醋酸锌、乙酰丙酮锌、碘化锌、溴化锌、氯化锌、氟化锌、碳酸锌、氰化锌、硝酸锌、氧化锌、过氧化锌、高氯酸锌、硫酸锌、油酸锌或硬脂酸锌中的至少一种。
所述的纳米材料的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Cd的前驱体，所述Cd的前驱体为二甲基镉、二乙基镉、醋酸镉、乙酰丙酮镉、碘化镉、溴化镉、氯化镉、氟化镉、碳酸镉、硝酸镉、氧化镉、高氯酸镉、磷酸镉、硫酸镉、油酸镉或硬脂酸镉中的至少一种。
所述的纳米材料的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Se的前驱体，所述Se的前驱体为Se‐TOP、Se‐TBP、Se‐TPP、Se‐ODE、Se‐OA、Se‐ODA、Se‐TOA、Se‐ODPA或Se‐OLA中的至少一种。
所述的纳米材料的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括S的前驱体，所述S的前驱体为S‐TOP、S‐TBP、S‐TPP、S‐ODE、S‐OA、S‐ODA、S‐TOA、S‐ODPA、S‐OLA或烷基硫醇中的至少一种。
所述的纳米材料的制备方法，其中，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Te的前驱体，所述Te的前驱体为Te‐TOP、Te‐TBP、Te‐TPP、Te‐ODE、Te‐OA、Te‐ODA、Te‐TOA、Te‐ODPA或Te‐OLA中的至少一种。
所述的纳米材料的制备方法，其中，在加热条件下使第一种化合物和第二种化合物体之间发生阳离子交换反应。
所述的纳米材料的制备方法，其中，加热温度在100℃至400℃之间。
所述的纳米材料的制备方法，其中，加热时间在2s至24h之间。
所述的纳米材料的制备方法，其中，在合成第一种化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50之间。
所述的纳米材料的制备方法，其中，在合成第二种化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50之间。
一种半导体器件，其中，包括如上任一项所述的纳米材料。
所述的半导体器件，其中，所述半导体器件为电致发光器件、光致发光器件、太阳能电池、显示器件、光电探测器、生物探针以及非线性光学器件中的任意一种。
有益效果：本发明提供了一种具有从内到外沿径向方向的全渐变合金组分的纳米材料，其不仅实现了更高效的发光效率，同时也更能满足半导体器件及相应显示技术对纳米材料的综合性能要求，是一种适合半导体器件及显示技术的理想纳米材料。
附图说明
图1为本发明一种纳米材料较佳实施例的能级结构曲线。
图2为本发明实施例13中量子点发光二极管的结构示意图。
图3为本发明实施例14中量子点发光二极管的结构示意图。
图4为本发明实施例15中量子点发光二极管的结构示意图。
图5为本发明实施例16中量子点发光二极管的结构示意图。
图6为本发明实施例17中量子点发光二极管的结构示意图。
图7为本发明实施例18中量子点发光二极管的结构示意图。
具体实施方式
本发明提供一种纳米材料、制备方法及半导体器件，为使本发明的目的、技术方案及效果更加清楚、明确，以下对本发明进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。
本发明所提供的一种纳米材料，其中，所述纳米材料包括N个在径向方向上依次排布的纳米结构单元，其中N≥2；
所述纳米结构单元包括A1和A2类型，所述A1类型为径向方向上能级宽度一致的均一合金组分结构；所述A2类型为径向方向上越向外能级宽度越宽的渐变合金组分结构；此处的径向方向是指从纳米材料的中心向外的方向，例如假设本发明的纳米材料为球形或类似球形结构，那么该径向方向即指沿半径的方向，纳米材料的中心即指其物理结构的中心，纳米材料的表面即指其物理结构的表面。
所述纳米材料的内部由至少一层A1类型的纳米结构单元组成，所述纳米材料的外部由至少一层A2类型的纳米结构单元组成；
在径向方向上相邻的纳米结构单元中，靠近纳米材料中心的纳米结构单元的能级宽度不大于远离纳米材料中心的纳米结构单元的能级宽度，且相邻的渐变合金组分结构的纳米结构单元的能级是连续的；也就是说当所述发光材料的外部包括至少两层A2类型的纳米结构单元时，则所述相邻的A2类型的纳米结构单元的能级是连续的；即本发明中各个相邻的渐变合金组分结构的纳米结构单元的能级宽度具有连续变化的特点，而非突变结构，也就是说纳米材料的外部合成组分具有连续性，这种特性更有利于实现高的发光效率。
本发明中的纳米材料，属于量子阱能级结构，其能级结构如图1所示。即所述的纳米材料中，其纳米结构单元的分布为A1…A1A2…A2，即所述纳米材料的内部是由A1类型的纳米结构单元组成，所述纳米材料的外部是由 A2类型的纳米结构单元组成，且A1类型的纳米结构单元的数量和A2类型的纳米结构单元的数量均大于等于1；
在A1类型的纳米结构单元中，其能级宽度是均一的；在A2类型的纳米结构单元中，其能级宽度是越向外越宽；在径向方向上相邻的纳米结构单元中，靠近中心的纳米结构单元的能级宽度不大于远离中心的纳米结构单元的能级宽度；且相邻纳米结构单元的能级宽度具有连续结构。在具体实施例中称图1的能级结构为量子阱能级结构。
进一步，所述合金纳米结构单元包含II族和VI族元素，即所述A1类型的纳米结构单元为包含II族和VI族元素的均一合金组分结构；所述A2类型的纳米结构单元为包含II族和VI族元素的渐变合金组分结构。所述II族元素包括但不限于Zn、Cd、Hg、Cn等。所述VI族元素包括但不限于O、S、Se、Te、Po、Lv等。
进一步，所述A1类型的纳米结构单元的合金组分为Cdx0Zn1‐x0Sey0S1‐y0，其中0≤x0≤1，0≤y0≤1，并且x0和y0不同时为0和不同时为1，且x0和y0在相应A1类型的纳米结构单元内为固定值。例如某一点的合金组分为Cd0.5Zn0.5Se0.5S0.5，而另一点的合金组分也应为Cd0.5Zn0.5Se0.5S0.5。
进一步，所述A2类型的纳米结构单元的合金组分组成为Cdx1Zn1‐x1Sey1S1‐y1，其中0≤x1≤1，0≤y1≤1，并且x1和y1不同时为0和不同时为1。例如某一点的合金组分为Cd0.5Zn0.5Se0.5S0.5，而另一点的合金组分为Cd0.3Zn0.7Se0.4S0.6。
具体地，所述A2类型的纳米结构单元中，A点的合金组分为Cdx AZn1‐x ASey AS1‐y A，B点的合金组分为Cdx BZn1‐x BSey BS1‐y B，其中A点相对于B点更靠近纳米材料的中心，且A点和B点的组成满足：x A>x B，y A>y B。也就是说，对于A2类型纳米结构单元中的任意两点A点和B点，且A点相对于B点更靠近纳米材料的中心，那么x A>x B，y A>y B，即A点的Cd含量大于B点的Cd含量，A点的Zn含量小于B点的Zn含量，A点的Se含量大于B点的Se 含量，A点的S含量小于B点的S含量。这样，在A2类型纳米结构单元中，就在径向方向上形成了渐变结构，并且由于在径向方向上，越向外(即远离纳米材料的中心)则Cd和Se含量越低，Zn和S含量越高，那么根据这几种元素的特性，其能级宽度将会越宽。
进一步，所述纳米结构单元包含2‐20层的单原子层。即，每一个纳米结构单元都包含2‐20层的单原子层。优选的为2个单原子层至5个单原子层，优选的层数能够保证量子点实现良好的发光量子产率以及高效的电荷注入效率。
进一步的，A1类型和A2类型纳米结构单元中的每一单原子层均为最小结构单元，即每一层的单一原子层其合金组分均是固定的，而相邻的两个单原子层之间可能会形成渐变合金组分结构，例如，在A2类型的纳米结构单元中，远离纳米材料中心的单原子层，其Cd和Se含量低，Zn和S含量高，靠近纳米材料中心的单原子层，其Cd和Se含量低，Zn和S含量高，从而形成渐变合金组分结构。但在A1类型的纳米结构单元中，每一层的单原子层其合金组分相同，以形成均一合金组分结构。
或者，所述A1类型和A2类型纳米结构单元均包含1‐10层的晶胞层，即每一纳米结构单元均包含1‐10层的晶胞层，例如包含2‐5层的晶胞层。晶胞层为最小结构单元，即每一层的晶胞层，其合金组分均是固定的，即每一晶胞层内具有相同晶格参数和元素。每一纳米结构单元均为晶胞层连续连接而构成的封闭晶胞曲面。
进一步，在径向方向上相邻的渐变合金组分结构的纳米结构单元交界处的两个单原子层之间形成连续合金组分结构。即，两个渐变合金组分结构的纳米结构单元交界处的两个单原子层之间是连续合金组分结构，也即其能级宽度也是渐变的，而不是突变的。或者，在径向方向上相邻的渐变合金组分结构的量子点结构单元交界处的两个晶胞层之间形成连续合金组分结构。上述提到的相邻的渐变合金组分结构的纳米结构单元为相邻的A2 类型的纳米结构单元。
也就是说，本发明的纳米材料，在相邻的A2类型纳米结构单元之间具有从内到外沿径向方向的连续合金组分。这种量子点结构在组成成分上具有有从内到外沿径向方向连续变化的特点，相对于具有明确边界的量子点核和壳的关系，本发明的纳米材料不仅有利于实现更高效的发光效率，同时也更能满足半导体器件及相应显示技术对纳米材料的综合性能要求，是一种适合半导体器件及显示技术的理想量子点纳米材料。
本发明采用上述结构的纳米材料，能够实现的发光量子产率范围为1％至100％，优选的发光量子产率范围为30％至100％，优选的发光量子产率范围内能够保证量子点的良好应用性。
本发明采用上述结构的纳米材料，能够实现的发光峰波长范围为400纳米至700纳米，优选的发光峰波长范围为430纳米至660纳米，优选的量子点发光峰波长范围能够保证纳米材料在此范围内实现大于30％的发光量子产率。
本发明中，所述纳米材料的发光峰的半高峰宽为12纳米至80纳米。
本发明所提供的纳米材料具有如下有益效果：第一，有助于最大程度上减少不同合金组分的量子点晶体间的晶格张力并缓解晶格失配，从而减少了界面缺陷的形成，提高了量子点的发光效率。第二，本发明所提供的纳米材料所形成的能级结构更有利于对量子点中电子云的有效束缚，大大减少电子云向量子点表面的扩散几率，从而极大地抑制了量子点无辐射跃迁的俄歇复合损失，减少量子点闪烁并提高量子点发光效率。第三，本发明所提供的纳米材料所形成的能级结构更有利于提高半导体器件中量子点发光层电荷的注入效率和传输效率；同时能够有效避免电荷的聚集以及由此产生的激子淬灭。第四，本发明所提供的量子点材料所形成的易于控制的多样性能级结构能够充分满足并配合器件中其他功能层的能级结构，以实现器件整体能级结构的匹配，从而有助于实现高效的半导体器件。
一种如上所述的纳米材料的制备方法，其中，包括步骤：
在预定位置处合成第一种化合物；
在第一种化合物的表面合成第二种化合物，所述第一种化合物与所述第二种化合物的合金组分相同或者不同；
使第一种化合物和第二种化合物体之间发生阳离子交换反应形成纳米材料，所述纳米材料的发光峰波长先不变，而后出现蓝移。
本发明的制备方法将量子点SILAR合成法结合量子点一步合成法生成纳米材料，具体为利用量子点逐层生长以及利用量子点一步合成法形成渐变组分过渡壳。即在预定位置处先后形成两层具有相同或者不同合金组分的化合物薄层，通过使两层化合物之间发生阳离子交换反应，从而实现在预定位置处的合金组分分布。重复以上过程可以不断实现在径向方向预定位置处的合金组分分布。
所述的第一种化合物和第二种化合物可以是二元或者二元以上化合物。
进一步，所述纳米材料的发光峰波长先不变后蓝移，若发光峰波长不变则代表能级宽度不变，若出现蓝移则代表发光峰向短波方向移动，即能级宽度变宽，如图1所示，在量子点径向方向上，在第一区间能级宽度不变，在第二区间内能级宽度变宽(蓝移)。
所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括：Zn的前驱体，所述Zn的前驱体为二甲基锌(dimethyl Zinc)、二乙基锌(diethyl Zinc)、醋酸锌(Zinc acetate)、乙酰丙酮锌(Zinc acetylacetonate)、碘化锌(Zinc iodide)、溴化锌(Zinc bromide)、氯化锌(Zinc chloride)、氟化锌(Zinc fluoride)、碳酸锌(Zinc carbonate)、氰化锌(Zinc cyanide)、硝酸锌(Zinc nitrate)、氧化锌(Zinc oxide)、过氧化锌(Zinc peroxide)、高氯酸锌(Zinc perchlorate)、硫酸锌(Zinc sulfate)、油酸锌(Zinc oleate)或硬脂酸锌(Zinc stearate)等中的至少一种，但不限于此。
所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Cd的 前驱体，所述Cd的前驱体为二甲基镉(dimethyl cadmium)、二乙基镉(diethyl cadmium)、醋酸镉(cadmium acetate)、乙酰丙酮镉(cadmium acetylacetonate)、碘化镉(cadmium iodide)、溴化镉(cadmium bromide)、氯化镉(cadmium chloride)、氟化镉(cadmium fluoride)、碳酸镉(cadmium carbonate)、硝酸镉(cadmium nitrate)、氧化镉(cadmium oxide)、高氯酸镉(cadmium perchlorate)、磷酸镉(cadmium phosphide)、硫酸镉(cadmium sulfate)、油酸镉(cadmium oleate)或硬脂酸镉(cadmium stearate)等中的至少一种，但不限于此。
所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Se的前驱体，例如Se与一些有机物任意组合所形成的化合物，具体是Se‐TOP(selenium‐trioctylphosphine)、Se‐TBP(selenium‐tributylphosphine)、Se‐TPP(selenium‐triphenylphosphine)、Se‐ODE(selenium‐1‐octadecene)、Se‐OA(selenium‐oleic acid)、Se‐ODA(selenium‐octadecylamine)、Se‐TOA(selenium‐trioctylamine)、Se‐ODPA(selenium‐octadecylphosphonic acid)或Se‐OLA(selenium‐oleylamine)等中的至少一种，但不限于此。
所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括S的前驱体，例如S与一些有机物任意组合所形成的化合物，具体是S‐TOP(sulfur‐trioctylphosphine，)、S‐TBP(sulfur‐tributylphosphine)、S‐TPP(sulfur‐triphenylphosphine)、S‐ODE(sulfur‐1‐octadecene)、S‐OA(sulfur‐oleic acid)、S‐ODA(sulfur‐octadecylamine)、S‐TOA(sulfur‐trioctylamine)、S‐ODPA(sulfur‐octadecylphosphonic acid)或S‐OLA(sulfur‐oleylamine)等，但不限于此；所述S的前驱体还可以烷基硫醇(alkyl thiol)，所述烷基硫醇可以是己硫醇(hexanethiol)、辛硫醇(octanethiol)、癸硫醇(decanethiol)、十二烷基硫醇(dodecanethiol)、十六烷基硫醇(hexadecanethiol)or巯丙基硅烷(mercaptopropylsilane)等中的至少一种，但不限于此。
所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Te的 前驱体，所述Te的前驱体为Te‐TOP、Te‐TBP、Te‐TPP、Te‐ODE、Te‐OA、Te‐ODA、Te‐TOA、Te‐ODPA或Te‐OLA中的至少一种。
上述阳离子前躯体和阴离子前驱体可以根据最终的纳米材料组成来确定选择其中的一种或几种：例如需要合成CdxZn1‐xSeyS1‐y的纳米材料时，则需要Cd的前驱体、Zn的前驱体、Se的前驱体、S的前驱体；如需要合成CdxZn1‐xS的纳米材料时，则需要Cd的前驱体、Zn的前驱体、S的前驱体；如需要合成CdxZn1‐xSe的纳米材料时，则需要Cd的前驱体、Zn的前驱体、Se的前驱体。
在本发明的制备方法中，发生阳离子交换反应的条件优选是进行加热反应，例如加热温度在100℃至400℃之间，优选的加热温度为150℃至380℃之间。加热时间在2s至24h之间，优选的加热时间为5min至4h之间。
加热温度越高，阳离子交换反应的速率越快，阳离子交换的厚度范围和交换程度也越大，但厚度和程度范围会逐渐达到相对饱和的程度；类似的，加热时间越长，阳离子交换的厚度范围和交换程度也越大，但厚度和程度范围也会逐渐达到相对饱和的程度。阳离子交换的厚度范围和程度直接决定了所形成的渐变合金组分分布。阳离子交换所形成的渐变合金组分分布同时也由各自所形成的二元或者多元化合物纳米材料的厚度所决定。
在形成各层化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50(具体为阳离子与阴离子的摩尔投料比)，例如在形成第一层化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50；在形成第二层化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50，优选的比例为20:1到1:10，优选的阳离子前驱体与阴离子前驱体的摩尔比例可以保证反应速率在易于控制的范围内。
通过上述制备方法所制备的纳米材料，其发光峰波长范围为400纳米至700纳米，优选的发光峰波长范围为430纳米至660纳米，优选的量子 点发光峰波长范围能够保证量子点在此范围内实现大于30％的发光量子产率。
以上制备方法所制备的纳米材料，发光量子产率范围为1％至100％，优选的发光量子产率范围为30％至100％，优选的发光量子产率范围内能够保证量子点的良好应用性。
除了按照上述制备方法制备本发明的纳米材料之外，本发明还提供另外一种如上所述的纳米材料的制备方法，其包括步骤：
在径向方向上预定位置处加入一种或一种以上阳离子前驱体；在一定条件下同时加入一种或一种以上的阴离子前驱体，使阳离子前驱体与阴离子前驱体进行反应形成纳米材料，并且所述纳米材料的发光峰波长在反应过程中先不变后出现蓝移，从而实现在指定位置处的渐变合金组分分布。
对于此种方法与前一种方法的不同在于，前一种是先后形成两层化合物，然后发生阳离子交换反应，从而实现渐变合金组分分布，而后一种方法是直接控制在预定位置处加入所需合成合金组分的阳离子前驱体和阴离子前驱体，进行反应形成纳米材料，从而实现本发明渐变合金组分分布。对于后一种方法，反应原理是反应活性高的阳离子前驱体和阴离子前驱体先发生反应，反应活性低的阳离子前驱体和阴离子前驱体后发生反应，并且在反应过程中，不同的阳离子发生阳离子交换反应，从而实现本发明渐变合金组分分布。至于阳离子前驱体与阴离子前驱体的种类在前述方法中已有详述。至于反应温度、反应时间和配比等可根据具体所需合成的纳米材料不同而有所不同，其与前述的前一种方法大体相同，后续以具体实施例进行说明。
本发明还提供一种半导体器件，其包括如上任一项所述的纳米材料。
所述半导体器件为电致发光器件、光致发光器件、太阳能电池、显示器件、光电探测器、生物探针以及非线性光学器件中的任意一种。
以电致发光器件为例，以本发明所述的纳米材料作为发光层材料的量 子点电致发光器件。这种量子点电致发光器件能够实现：1)高效电荷注入、2)高发光亮度、3)低驱动电压、4)高器件效率等优异器件性能。同时，本发明所述的纳米材料，具有易于控制和多样性能级结构的特点，能够充分满足并配合器件中其他功能层的能级结构，以实现器件整体能级结构的匹配，从而有助于实现高效稳定的半导体器件。
所述光致发光器件是指依赖外界光源进行照射，从而获得能量，产生激发导致发光的器件，紫外辐射、可见光及红外辐射均可引起光致发光，例如磷光与荧光。本发明的纳米材料可作为光致发光器件的发光材料。
所述太阳能电池也称光伏器件，本发明的纳米材料可作为太阳能电池的光吸收材料，有效提高光伏器件的各项性能。
所述显示器件是指背光模组或应用所述背光模组的显示面板，所述显示面板可以应用在各种产品当中，例如显示器、平板电脑、手机、笔记本电脑、平板电视、可穿戴式显示设备或其他包含不同尺寸显示面板的产品。
所述光电探测器是指能把光信号转换为电信号的器件，其原理是由辐射引起被照射材料电导率发生改变，将量子点材料应用在光电探测器中，具有如下优势：对垂直入射光敏感、光电导响应度高、比探测率高、探测波长连续可调及可低温制备。这种结构的光电探测器在运行过程中，量子点光敏层(即采用本发明的纳米材料)吸收光子后产生的光生电子‐空穴对能够在内建电场的作用下发生分离，这使得该结构光电探测器具有更低的驱动电压，能在低外加偏压甚至是0外加偏压下就能工作，且易于控制。
所述生物探针是指对某类材料进行修饰，使其具有标记功能的器件，例如对本发明的纳米材料进行包覆，从而形成荧光探针，应用在细胞成像或者物质检测领域中，相对于传统的有机荧光染料探针，采用本发明的纳米材料制备的生物探针，具有荧光强度高、化学稳定性好、抗光漂白能力强的特点，具有广泛的用途。
所述非线性光学器件属于光学激光技术领域，其应用较广泛，例如用于电 光开光和激光调制，用于激光频率的转换、激光频率的调谐；进行光学信息处理、改善成像质量和光束质量；作为非线性标准具和双稳器件；研究物质的高激发态以及高分辨率光谱以及物质内部能量和激发的转移过程以及其他弛豫过程等。
实施例1：基于CdZnSeS/CdZnSeS量子点的制备
先将阳离子Cd的前驱体、阳离子Zn的前驱体、阴离子Se的前驱体和阴离子S的前驱体注入到反应体系中，形成CdyZn1‐ySebS1‐b层(其中0≤y≤1，0≤b≤1)；继续将阳离子Cd的前驱体、阳离子Zn的前驱体、阴离子Se的前驱体和阴离子S的前驱体注入到反应体系中，在上述CdyZn1‐ySebS1‐b层表面形成CdzZn1‐zSecS1‐c层(其中0≤z≤1，且z不等于y，0≤c≤1)；在一定的加热温度和加热时间等反应条件下，发生内外层纳米晶体(即上述两层化合物)中Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdyZn1‐ySebS1‐b层与CdzZn1‐zSecS1‐c层的界面附近形成Cd含量和Zn含量的渐变合金组分分布，即CdxZn1‐xSeaS1‐a，其中0≤x≤1，0≤a≤1。
实施例2：基于CdZnS/CdZnS量子点的制备
先将阳离子Cd的前驱体、阳离子Zn的前驱体以及阴离子S的前驱体注入到反应体系中，先形成CdyZn1‐yS层(其中0≤y≤1)；继续将阳离子Cd的前驱体、阳离子Zn的前驱体以及阴离子S的前驱体注入到反应体系中，会在上述CdyZn1‐yS层表面形成CdzZn1‐zS层(其中0≤z≤1，且z不等于y)；在一定的加热温度和加热时间等反应条件下，发生内外层纳米晶体(即上述两层化合物)中Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdyZn1‐yS层与CdzZn1‐zS层的界面附近形成Cd含量和Zn含量的渐变合金组分分布，即CdxZn1‐xS，其中0≤x≤1。
实施例3：基于CdZnSe/CdZnSe量子点的制备
先将阳离子Cd的前驱体、阳离子Zn的前驱体以及阴离子Se的前驱体注入到反应体系中先形成CdyZn1‐ySe层(其中0≤y≤1)；继续将阳离子Cd的前驱体、阳离子Zn的前驱体以及阴离子Se的前驱体注入到反应体系中，会在上述CdyZn1‐ySe层表面形成CdzZn1‐zSe层(其中0≤z≤1，且z不等于y)；在一定的加热温度和加热时间等反应条件下，发生内外层纳米晶体中Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdyZn1‐ySe层与CdzZn1‐zSe层的界面附近形成Cd含量和Zn含量的渐变合金组分分布，即CdxZn1‐xSe，其中0≤x≤1。
实施例4：基于CdS/ZnS量子点的制备
先将阳离子Cd的前驱体和阴离子S的前驱体注入到反应体系中，先形成CdS层；继续将阳离子Zn的前驱体和阴离子S的前驱体注入到反应体系中，会在上述CdS层表面形成ZnS层；在一定的加热温度和加热时间等反应条件下，外层的Zn阳离子会逐渐向内层迁移，并与Cd阳离子发生阳离子交换反应，即Cd离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdS层与ZnS层的界面附近形成Cd含量沿着径向向外逐渐减少、Zn含量沿着径向向外逐渐增加的渐变合金组分分布，即CdxZn1‐xS，其中0≤x≤1且x自内向外(径向方向)从1单调递减为0。
实施例5：基于CdSe/ZnSe量子点的制备
先将阳离子Cd的前驱体和阴离子Se的前驱体注入到反应体系中先形成CdSe层；继续将阳离子Zn的前驱体和阴离子Se的前驱体注入到反应体系中，会在上述CdSe层表面形成ZnSe层；在一定的加热温度和加热时间等反应条件下，外层的Zn阳离子会逐渐向内层迁移，并与Cd阳离子发生阳离子交换反应，即Cd离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdSe层与ZnSe层的界面附近形成Cd含量沿着径向向外逐渐减少、Zn 含量沿着径向向外逐渐增加的渐变合金组分分布，即CdxZn1‐xSe，其中0≤x≤1且x自内向外(径向方向)从1单调递减为0。
实施例6：基于CdSeS/ZnSeS量子点的制备
先将阳离子Cd的前驱体、阴离子Se的前驱体以及阴离子S的前驱体注入到反应体系中先形成CdSebS1‐b层(其中0≤b≤1)；继续将阳离子Zn的前驱体、阴离子Se的前驱体以及阴离子S的前驱体注入到反应体系中，会在上述CdSebS1‐b层表面形成ZnSecS1‐c层(其中0≤c≤1)；在一定的加热温度和加热时间等反应条件下，外层的Zn阳离子会逐渐向内层迁移，并与Cd阳离子发生阳离子交换反应，即Cd离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在CdSebS1‐b层与ZnSecS1‐c层的界面附近形成Cd含量沿着径向向外逐渐减少、Zn含量沿着径向向外逐渐增加的渐变合金组分分布，即CdxZn1‐xSeaS1‐a，其中0≤x≤1且x自内向外(径向方向)从1单调递减为0，0≤a≤1。
实施例7：基于ZnS/CdS量子点的制备
先将阳离子Zn的前驱体和阴离子S的前驱体注入到反应体系中先形成ZnS层；继续将阳离子Cd的前驱体和阴离子S的前驱体注入到反应体系中，会在上述ZnS层表面形成CdS层；在一定的加热温度和加热时间等反应条件下，外层的Cd阳离子会逐渐向内层迁移，并与Zn阳离子发生阳离子交换反应，即Zn离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在ZnS层与CdS层的界面附近形成Zn含量沿着径向向外逐渐减少、Cd含量沿着径向向外逐渐增加的渐变合金组分分布，即CdxZn1‐xS，其中0≤x≤1且x自内向外(径向方向)从0单调递增为1。
实施例8：基于ZnSe/CdSe量子点的制备
先将阳离子Zn的前驱体和阴离子Se的前驱体注入到反应体系中先形 成ZnSe层；继续将阳离子Cd的前驱体和阴离子Se的前驱体注入到反应体系中，会在上述ZnSe层表面形成CdSe层；在一定的加热温度和加热时间等反应条件下，外层的Cd阳离子会逐渐向内层迁移，并与Zn阳离子发生阳离子交换反应，即Zn离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在ZnSe层与CdSe层的界面附近形成Zn含量沿着径向向外逐渐减少、Cd含量沿着径向向外逐渐增加的渐变合金组分分布，即CdxZn1‐xSe，其中0≤x≤1且x自内向外(径向方向)从0单调递增为1。
实施例9：基于ZnSeS/CdSeS量子点的制备
先将阳离子Zn的前驱体、阴离子Se的前驱体以及阴离子S的前驱体注入到反应体系中先形成ZnSebS1‐b层(其中0≤b≤1)；继续将阳离子Cd的前驱体、阴离子Se的前驱体以及阴离子S的前驱体注入到反应体系中，会在上述ZnSebS1‐b层表面形成CdSecS1‐c层(其中0≤c≤1)；在一定的加热温度和加热时间等反应条件下，外层的Cd阳离子会逐渐向内层迁移，并与Zn阳离子发生阳离子交换反应，即Zn离子向外层迁移，发生了Cd与Zn离子的互换；由于阳离子的迁移距离有限且越远的迁移距离发生迁移的机率就越小，因此会在ZnSebS1‐b层与CdSecS1‐c层的界面附近形成Zn含量沿着径向向外逐渐减少、Cd含量沿着径向向外逐渐增加的渐变合金组分分布，即CdxZn1‐xSeaS1‐a，其中0≤x≤1且x自内向外从0单调递增为1，0≤a≤1。
实施例10：具有量子阱能级结构的蓝色量子点的制备
油酸镉第一前驱体制备：将1mmol氧化镉(CdO)，1mL油酸(Oleic acid)和5mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60mins。然后将其切换成氮气气氛下，并于该温度下保存以备待用。
油酸镉第二前驱体制备：将0.6mmol氧化镉(CdO)，0.6mL油酸(Oleic acid)和5.4mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，在氮气 氛围下250℃加热回流120mins，得到透明的油酸镉第二前驱体。
油酸锌前驱体制备：将9mmol乙酸锌[Zn(acet)2]，7mL油酸(Oleic acid)，和10mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60mins。然后将其切换成氮气气氛下，并于氮气氛围下250℃加热回流保存以备待用。
将2mmol硫粉(Sulfur powder)溶解在3mL的十八烯(1‐Octadecene)中，得到硫十八烯前驱体。
将6mmol硫粉(Sulfur powder)溶解在3mL的三辛基膦(Trioctylphosphine)中，得到硫化三辛基膦前驱体。
在氮气氛围下，将油酸镉第一前驱体升温至310℃，将硫十八烯前驱体快速注入到反应体系中，迅速生成CdS，反应10mins后，将油酸锌前驱体全部注入反应体系，随后将3mL的硫化三辛基膦前驱体和6mL油酸镉第二前驱体分别以3mL/h和10mL/h的速率同时注入到反应体系中。
反应结束后，待反应液冷却至室温后，用甲苯和无水甲醇将产物反复溶解、沉淀，离心提纯，得到具有量子阱能级结构的蓝色量子点。
实施例11：具有量子阱能级结构的绿色量子点的制备
油酸镉前驱体制备：将0.4mmol氧化镉(CdO)，1mL油酸(Oleic acid)和5mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60mins。然后将其在氮气氛围下250℃加热回流，并于该温度下保存以备待用。
将0.4mmol硒粉(Selenium powder)，溶解在4mL的三辛基膦(Trioctylphosphine)中，得到硒化三辛基膦。
油酸锌前驱体制备：将8mmol乙酸锌[Zn(acet)2]，9mL油酸(Oleic acid)和15mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60mins。在氮气氛围下250℃加热回流120mins，得到透明的油酸锌前驱体。
将2mmol硫粉(Sulfur powder)和1.6mmol硒粉(Selenium powder)溶解在2mL的三辛基膦(Trioctylphosphine)中，得到硒化三辛基膦‐硫化三辛基膦前驱体。
在氮气氛围下，将油酸镉前驱体升温至310℃，将硒化三辛基膦前驱体快速注入到反应体系中，迅速生成CdSe，反应5mins后，将油酸锌前驱体全部注入到反应体系中，将2mL的硒化三辛基膦‐硫化三辛基膦前驱体以2mL/h的速率逐滴加入到反应体系中，直至前驱体注入完。反应结束后，待反应液冷却至室温后，用甲苯和无水甲醇将产物反复溶解、沉淀，离心提纯，得到具有量子阱能级结构的绿色荧光量子点。
实施例12：具有量子阱能级结构的红色量子点的制备
油酸镉前驱体制备：将0.8mmol氧化镉(CdO)，4mL油酸(Oleic acid)和10mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60mins。然后将其在氮气氛围下250℃加热回流，并于该温度下保存以备待用。
油酸锌前驱体制备：12mmol乙酸锌[Zn(acet)2]，10mL油酸(Oleic acid)和10mL十八烯(1‐Octadecene)置于100mL三口烧瓶中，于80℃下进行真空脱气60mins。
将0.8mmol硒粉(Selenium powder)在4mL的三辛基膦(Trioctylphosphine)中，得到硒化三辛基膦前驱体。
将1mmol硒粉(Selenium powder)，0.6mmol硫粉(Sulfur powder)溶解在2mL的三辛基膦(Trioctylphosphine)中，得到硒化三辛基膦‐硫化三辛基膦前驱体。
在氮气氛围下，将油酸镉前驱体升温至310℃，将硒化三辛基膦前驱体快速注入到反应体系中，迅速生成CdSe，反应10mins后，将油酸锌前驱体全部注入到反应体系中，将2mL的硒化三辛基膦‐硫化三辛基膦前驱体以4mL/h的速率逐滴加入到反应体系中。反应结束后，待反应液冷却至室温 后，用甲苯和无水甲醇将产物反复溶解、沉淀，离心提纯，得到具有量子阱能级结构的红色荧光量子点。
实施例13
本实施例量子点发光二极管，如图2所示，自下而上依次包括：ITO衬底11、底电极12、PEDOT：PSS空穴注入层13、poly‐TPD空穴传输层14、量子点发光层15、ZnO电子传输层16及Al顶电极17。
上述量子点发光二极管的制备步骤如下：
在ITO衬底11上依次制备底电极12、30nm PEDOT：PSS空穴注入层13和30nm poly‐TPD空穴传输层14后，在poly‐TPD空穴传输层14上制备一层量子点发光层15，厚度为20nm，随后再在量子点发光层15上制备40nm ZnO电子传输层16及100nm Al顶电极17。所述量子点发光层15的纳米材料为如实施例10所述的纳米材料。
实施例14
本实施例中量子点发光二极管，如图3所示，自下而上依次包括：ITO衬底21、底电极22、PEDOT：PSS空穴注入层23、Poly(9‐vinylcarbazole)(PVK)空穴传输层24、量子点发光层25、ZnO电子传输层26及Al顶电极27。
上述量子点发光二极管的制备步骤如下：
在ITO衬底21上依次制备底电极22、30nm PEDOT：PSS空穴注入层23和30nm PVK空穴传输层24后，在PVK空穴传输层24上制备一层量子点发光层25，厚度为20nm，随后再在量子点发光层25上制备40nm ZnO电子传输层26及100nm Al顶电极27。所述量子点发光层25的纳米材料为如实施例11所述的纳米材料。
实施例15
本实施例量子点发光二极管，如图4所示，自下而上依次包括：ITO衬底31、底电极32、PEDOT：PSS空穴注入层33、poly‐TPD空穴传输层34、量子点发光层35、TPBi电子传输层36及Al顶电极37。
上述量子点发光二极管的制备步骤如下：
在ITO衬底31上依次制备底电极32、30nm PEDOT：PSS空穴注入层33和30nm poly‐TPD空穴传输层34后，在poly‐TPD空穴传输层34上制备一层量子点发光层35，厚度为20nm，随后再在量子点发光层35上通过真空蒸镀方法制备30nm TPBi电子传输层36及100nm Al顶电极37。所述量子点发光层35的纳米材料为如实施例12所述的纳米材料。
实施例16
本实施例量子点发光二极管，如图5所示，自下而上依次包括：ITO衬底41、底电极42、ZnO电子传输层43、量子点发光层44、NPB空穴传输层45、MoO3空穴注入层46及Al顶电极47。
上述量子点发光二极管的制备步骤如下：
在ITO衬底41上依次制备底电极42，40nm ZnO电子传输层43，在ZnO电子传输层43上制备一层量子点发光层44，厚度为20nm,随后再通过真空蒸镀方法制备30nm NPB空穴传输层45，5nm MoO3空穴注入层46及100nm Al顶电极47。所述量子点发光层44的纳米材料为如实施例10所述的纳米材料。
实施例17
本实施例量子点发光二极管，如图6所示，自下而上依次包括：玻璃衬底51、Al电极52，PEDOT：PSS空穴注入层53、poly‐TPD空穴传输层54、量子点发光层55、ZnO电子传输层56及ITO顶电极57。
上述量子点发光二极管的制备步骤如下：
在玻璃衬底51上通过真空蒸镀方法制备100nm Al电极52，然后依次制备30nm PEDOT：PSS空穴注入层53和30nm poly‐TPD空穴传输层54后，在poly‐TPD空穴传输层54上制备一层量子点发光层55，厚度为20nm，随后再在量子点发光层55上制备40nm ZnO电子传输层56，最后通过溅射方法制备120nm ITO作为顶电极57。所述量子点发光层55的纳米材料为如 实施例11所述的纳米材料。
实施例18
本实施例量子点发光二极管，如图7所示，自下而上依次包括：玻璃衬底61、Al电极62，ZnO电子传输层63，量子点发光层64，NPB空穴传输层65，MoO3空穴注入层66及ITO顶电极67。
上述量子点发光二极管的制备步骤如下：
在玻璃衬底61上通过真空蒸镀方法制备100nm Al电极62，然后依次制备40nm ZnO电子传输层63，20nm量子点发光层64，随后再通过真空蒸镀方法制备30nm NPB空穴传输层65，5nm MoO3空穴注入层66，最后通过溅射方法制备120nm ITO作为顶电极67。所述量子点发光层的纳米材料为如实施例12所述的纳米材料。
应当理解的是，本发明的应用不限于上述的举例，对本领域普通技术人员来说，可以根据上述说明加以改进或变换，所有这些改进和变换都应属于本发明所附权利要求的保护范围。

Claims (22)

  1. 一种纳米材料，其特征在于，所述纳米材料包括N个在径向方向上依次排布的纳米结构单元，其中N≥2；
    所述纳米结构单元包括A1和A2类型，所述A1类型为径向方向上能级宽度一致的均一组分结构；所述A2类型为径向方向上越向外能级宽度越宽的渐变合金组分结构；
    所述纳米材料的内部由至少一层A1类型的纳米结构单元组成，所述纳米材料的外部由至少一层A2类型的纳米结构单元组成；
    在径向方向上相邻的纳米结构单元中，靠近纳米材料中心的纳米结构单元的能级宽度不大于远离纳米材料中心的纳米结构单元的能级宽度，且相邻的渐变合金组分结构的量子点结构单元的能级是连续的。
  2. 根据权利要求1所述的纳米材料，其特征在于，所述A1类型的量子点结构单元为包含II族和VI族元素的均一合金组分结构，所述A2类型的量子点结构单元为包含II族和VI族元素的渐变合金组分结构。
  3. 根据权利要求2所述的纳米材料，其特征在于，所述A1类型的纳米结构单元的合金组分为Cdx0Zn1‐x0Sey0S1‐y0，其中0≤x0≤1，0≤y0≤1，并且x0和y0不同时为0和不同时为1，且x0和y0在相应A1类型的纳米结构单元内为固定值。
  4. 根据权利要求2所述的纳米材料，其特征在于，所述A2类型的纳米结构单元的合金组分组成为Cdx1Zn1‐x1Sey1S1‐y1，其中0≤x1≤1，0≤y1≤1，并且x1和y1不同时为0和不同时为1。
  5. 根据权利要求4所述的纳米材料，其特征在于，所述A2类型的纳米结构单元中，A点的合金组分分别为Cdx AZn1‐x ASey AS1‐y A，B点的合金组分为Cdx BZn1‐x BSey BS1‐y B，其中A点相对于B点更靠近纳米材料中心，且A点和B点的组成满足：x A>x B，y A>y B。
  6. 根据权利要求1所述的纳米材料，其特征在于，所述纳米结构单元包含2‐20层的单原子层，或者所述纳米结构单元包含1‐10层的晶胞层。
  7. 根据权利要求6所述的纳米材料，其特征在于，在径向方向上相邻的纳米结构单元交界处的两个单原子层之间形成连续合金组分结构，或者在径向方向上相邻的纳米结构单元交界处的两个晶胞层之间形成连续合金组分结构。
  8. 根据权利要求1所述的纳米材料，其特征在于，所述纳米材料的发光峰波长范围为400纳米至700纳米。
  9. 根据权利要求1所述的纳米材料，其特征在于，所述纳米材料的发光峰的半高峰宽为12纳米至80纳米。
  10. 一种如权利要求1所述的纳米材料的制备方法，其特征在于，包括步骤：
    在预定位置处合成第一种化合物；
    在第一种化合物的表面合成第二种化合物，所述第一种化合物与所述第二种化合物的合金组分相同或者不同；
    使第一种化合物和第二种化合物体之间发生阳离子交换反应形成纳米材料，所述纳米材料的发光峰波长先不变，而后出现蓝移。
  11. 根据权利要求8所述的纳米材料的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Zn的前驱体，所述Zn的前驱体为二甲基锌、二乙基锌、醋酸锌、乙酰丙酮锌、碘化锌、溴化锌、氯化锌、氟化锌、碳酸锌、氰化锌、硝酸锌、氧化锌、过氧化锌、高氯酸锌、硫酸锌、油酸锌或硬脂酸锌中的至少一种。
  12. 根据权利要求8所述的纳米材料的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阳离子前驱体包括Cd的前驱体，所述Cd的前驱体为二甲基镉、二乙基镉、醋酸镉、乙酰丙酮镉、碘化镉、溴化镉、氯化镉、氟化镉、碳酸镉、硝酸镉、氧化镉、高氯酸镉、磷酸镉、 硫酸镉、油酸镉或硬脂酸镉中的至少一种。
  13. 根据权利要求10所述的纳米材料的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Se的前驱体，所述Se的前驱体为Se‐TOP、Se‐TBP、Se‐TPP、Se‐ODE、Se‐OA、Se‐ODA、Se‐TOA、Se‐ODPA或Se‐OLA中的至少一种。
  14. 根据权利要求10所述的纳米材料的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括S的前驱体，所述S的前驱体为S‐TOP、S‐TBP、S‐TPP、S‐ODE、S‐OA、S‐ODA、S‐TOA、S‐ODPA、S‐OLA或烷基硫醇中的至少一种。
  15. 根据权利要求10所述的纳米材料的制备方法，其特征在于，所述第一种化合物和/或所述第二种化合物的阴离子前驱体包括Te的前驱体，所述Te的前驱体为Te‐TOP、Te‐TBP、Te‐TPP、Te‐ODE、Te‐OA、Te‐ODA、Te‐TOA、Te‐ODPA或Te‐OLA中的至少一种。
  16. 根据权利要求10所述的纳米材料的制备方法，其特征在于，在加热条件下使第一种化合物和第二种化合物体之间发生阳离子交换反应。
  17. 根据权利要求16所述的纳米材料的制备方法，其特征在于，加热温度在100℃至400℃之间。
  18. 根据权利要求16所述的纳米材料的制备方法，其特征在于，加热时间在2s至24h之间。
  19. 根据权利要求10所述的纳米材料的制备方法，其特征在于，在合成第一种化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50之间。
  20. 根据权利要求10所述的纳米材料的制备方法，其特征在于，在合成第二种化合物时，阳离子前驱体与阴离子前驱体的摩尔比为100:1到1:50之间。
  21. 一种半导体器件，其特征在于，包括如权利要求1～9任一项所述 的纳米材料。
  22. 根据权利要求21所述的半导体器件，其特征在于，所述半导体器件为电致发光器件、光致发光器件、太阳能电池、显示器件、光电探测器、生物探针以及非线性光学器件中的任意一种。
PCT/CN2017/080621 2016-12-30 2017-04-14 一种纳米材料、制备方法及半导体器件 WO2018120516A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201611260234.5A CN108269934A (zh) 2016-12-30 2016-12-30 一种纳米材料、制备方法及半导体器件
CN201611260234.5 2016-12-30

Publications (1)

Publication Number Publication Date
WO2018120516A1 true WO2018120516A1 (zh) 2018-07-05

Family

ID=62706804

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2017/080621 WO2018120516A1 (zh) 2016-12-30 2017-04-14 一种纳米材料、制备方法及半导体器件

Country Status (2)

Country Link
CN (1) CN108269934A (zh)
WO (1) WO2018120516A1 (zh)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102676174A (zh) * 2012-06-01 2012-09-19 广东普加福光电科技有限公司 CdZnSeS量子点的制备方法
CN104736234A (zh) * 2012-08-30 2015-06-24 应用纳米技术中枢(Can)有限公司 核-壳纳米颗粒的制备方法和核-壳纳米颗粒
CN104910918A (zh) * 2015-04-30 2015-09-16 中国科学院半导体研究所 一种核壳量子点材料及其制备方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2524350C (en) * 2003-05-07 2015-04-14 Indiana University Research & Technology Corporation Alloyed semiconductor quantum dots and concentration-gradient alloyed quantum dots, series comprising the same and methods related thereto
KR100817853B1 (ko) * 2006-09-25 2008-03-31 재단법인서울대학교산학협력재단 점진적 농도구배 껍질 구조를 갖는 양자점 및 이의 제조방법
US7777233B2 (en) * 2007-10-30 2010-08-17 Eastman Kodak Company Device containing non-blinking quantum dots
JP5744468B2 (ja) * 2010-10-20 2015-07-08 シャープ株式会社 半導体ナノ粒子蛍光体

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102676174A (zh) * 2012-06-01 2012-09-19 广东普加福光电科技有限公司 CdZnSeS量子点的制备方法
CN104736234A (zh) * 2012-08-30 2015-06-24 应用纳米技术中枢(Can)有限公司 核-壳纳米颗粒的制备方法和核-壳纳米颗粒
CN104910918A (zh) * 2015-04-30 2015-09-16 中国科学院半导体研究所 一种核壳量子点材料及其制备方法

Also Published As

Publication number Publication date
CN108269934A (zh) 2018-07-10

Similar Documents

Publication Publication Date Title
WO2018120513A1 (zh) 一种量子点复合材料、制备方法及半导体器件
WO2018120515A1 (zh) 一种量子点材料、制备方法及半导体器件
CN106601886B (zh) 具有量子阱能级结构的纳米晶体、制备方法及半导体器件
CN108264901B (zh) 具有漏斗型能级结构的发光材料、制备方法及半导体器件
WO2018120511A1 (zh) 一种量子点薄膜及其制备方法
CN108264894A (zh) 一种纳米发光材料、制备方法及半导体器件
WO2018120510A1 (zh) 一种量子点材料、制备方法及半导体器件
CN108269891B (zh) 一种纳米复合材料、制备方法及半导体器件
WO2018120517A1 (zh) 一种合金纳米材料、制备方法及半导体器件
WO2018120518A1 (zh) 一种纳米晶体、制备方法及半导体器件
CN108269892B (zh) 具有量子阱能级结构的合金材料、制备方法及半导体器件
WO2018120516A1 (zh) 一种纳米材料、制备方法及半导体器件
CN108264904A (zh) 一种发光材料、制备方法及半导体器件
WO2018120512A1 (zh) 一种量子点油墨及其制备方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17886579

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 04/10/2019)