CN109929558A

CN109929558A - A kind of quantum dot and preparation method thereof

Info

Publication number: CN109929558A
Application number: CN201711363565.6A
Authority: CN
Inventors: 杨一行; 聂志文
Original assignee: TCL Corp
Current assignee: TCL Corp
Priority date: 2017-12-18
Filing date: 2017-12-18
Publication date: 2019-06-25

Abstract

The present invention discloses a kind of quantum dot and preparation method thereof, wherein, the quantum dot includes quantum dot core, the first metal layer of coated quantum dots core, coat the first semiconductor shell of the first metal layer, the second metal layer for coating the first semiconductor shell coats the second semiconductor shell of second metal layer；Wherein, the metallic element in the metallic element and second metal layer in the first metal layer is independently selected from one of Zn, Hg, Al, Ga and In or a variety of.Metal layer can be bonded with quantum dot nuclear phase using the ligand on quantum dot core surface as connection tie, promote quantum dot core surface active, be conducive to further quantum dot outer semiconductor shell growth response；The metallic atom in metal layer is formed by crystal structure by above-mentioned be bonded with quantum dot core simultaneously, it can be effectively passivated quantum dot core surface, reduce its surface defect and reduce the lattice mismatch between nucleocapsid, to enhance the luminous efficiency and dimensional homogeneity of quanta point material.

Description

A kind of quantum dot and preparation method thereof

Technical field

The present invention relates to technology of quantum dots fields more particularly to a kind of quantum dot and preparation method thereof.

Background technique

Quantum dot is a kind of special material for being limited in nanometer scale in three dimensions, this significant quantum Confinement effect makes quantum dot be provided with many unique nanometer properties, as launch wavelength is continuously adjustable, emission wavelength is narrow, absorbs Spectral width, luminous intensity height, fluorescence lifetime length and good biocompatibility etc..These features mark quanta point material in biology The fields such as note, FPD, solid-state lighting, photovoltaic solar all have broad application prospect.

The size of quantum dot is usually in 20nm hereinafter, therefore the specific surface area of quanta point material is very big, the table of quantum dot Face characteristic and property influence highly significant for the performance of quantum dot.There is a large amount of dangling bonds for quantum dot surface, these are outstanding Hang a part is connected to be added in reaction process in key organic ligand (such as organic amine, organic carboxyl acid class, it is organic phosphorus, Mercaptan etc.), another part is then exposed to external environment, is easy to react with external environment, while exposed dangling bonds can be Defect state and defect level are formed in band gap, this is also to cause nonradiative transition to lose and lead to the reduction of quantum dot light emitting efficiency Major reason.Therefore, in order to improve the luminous efficiency of quantum dot, need to eliminate the suspension of quantum dot surface exposure as much as possible Key.The prior art generallys use two methods to eliminate the dangling bonds of quantum dot surface exposure, to effectively be passivated quantum dot: one It is by connecting organic ligand on exposed dangling bonds；Second is that partly being led outside by the way that continued growth is inorganic outside exposed dangling bonds Body shell layer.Therefore there is the quantum dot of core-shell structure to have become what realization quantum dot excellent optical property was generallyd use for preparation Scheme.

Be currently used in photoelectric field semiconductor Colloidal Quantum Dots be mostly by metallorganic pyrolyzing synthesis method come Preparation.In this approach, the reaction system of the presoma of anion and the first metal precursor reaches reaction at high temperature Object moment supersaturation, thus occur in the short time at nuclear reaction and subsequent growth response, ultimately form with good ruler The quantum dot of very little list distributivity.

In the semiconductor-quantum-point material system of photoelectric field, cadmium-free quantum dots are due to not only having quantum dot excellent The characteristics of luminescence and simultaneously be free of heavy metal cadmium (Cd) the characteristics of and more and more attention has been paid to.But in luminous efficiency and luminance purity In photovoltaic applications such as (shine peak width) in very important Indexes Comparison, the performance of cadmium-free quantum dots still can significant backwardness In classical cadmium content point system (such as CdSe).What the preparation of cadmium-free quantum dots generallyd use at present is and cadmium content point class As metallorganic thermally decompose hot injection method, no cadmium amount is similarly improved using nucleocapsid knot color quantum-dot structure design is upper The luminous efficiency and stability of material of son point.But presoma type and activity as used in cadmium-free quantum dots core, preparation Etc. with difference present in cadmium content point so that cadmium-free quantum dots in the formation of core-shell structure system to realize more Few crystal defect, more evenly the requirements such as size distribution can become more difficult, this is also the performance for causing current cadmium-free quantum dots The main reason for lagging behind cadmium content point system significantly.

Therefore, the existing technology needs to be improved and developed.

Summary of the invention

In view of above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a kind of quantum dot and preparation method thereof with answer With, it is intended to solve the problems, such as that the luminous efficiency of existing cadmium-free quantum dots material is lower.

Technical scheme is as follows:

A kind of quantum dot, wherein the quantum dot includes quantum dot core, coats the metal layer of the quantum dot core, described in cladding The semiconductor shell of metal layer, wherein the metallic element in the metal layer is selected from one of Zn, Hg, Al, Ga and In or more Kind.

The quantum dot, wherein the material of the quantum dot core is selected from III-V group semi-conductor material or iii-v half Alloy semiconductor material composed by conductor material and Group II-VI semiconductor material.

The quantum dot, wherein the material of the quantum dot core is III-V group semi-conductor material, the iii-v half Conductor material is selected from one of GaN, GaP, GaAs, InP, InAs, InAsP, GaAsP, InGaP, InGaAs and InGaAsP.

The quantum dot, wherein the material of the quantum dot core is that III-V group semi-conductor material is partly led with II-VI group Alloy semiconductor material composed by body material, the III-V group semi-conductor material be selected from GaN, GaP, GaAs, InP, InAs, One of InAsP, GaAsP, InGaP, InGaAs and InGaAsP, the Group II-VI semiconductor material be selected from ZnSe, ZnS, One of ZnTe, ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, HgSeS, HgSeTe and HgSTe.

The quantum dot, wherein the material of the semiconductor shell is Group II-VI semiconductor material.

The quantum dot, wherein the Group II-VI semiconductor material of the semiconductor shell be selected from ZnSe, ZnS, ZnTe, One of ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, HgSeS, HgSeTe and HgSTe.

The quantum dot, wherein the glow peak wave-length coverage of the quantum dot is 400-700 nanometers.

The quantum dot, wherein the peak width at half height range of the glow peak of the quantum dot is 20-100 nanometers.

The quantum dot, wherein the material of the quantum dot core is selected from InP or InGaP, the metal in the metal layer Element is selected from Zn or Ga；Further, the quantum dot, wherein the material of the semiconductor shells layer is selected from ZnSe, ZnS One of with ZnSeS.

The quantum dot, wherein the material of the quantum dot core is that III-V group semi-conductor material and II-VI group are partly led The metallic element of alloy semiconductor material composed by body material, the metal layer is selected from Zn.Further, the quantum Point, wherein alloy semiconductor material composed by the III-V group semi-conductor material and Group II-VI semiconductor material is selected from One of InPZnS, InPZnSe, InPZnSeS, InGaPZnSe, InGaPZnS and InGaPZnSeS.Further, described Quantum dot, wherein the material of the semiconductor shells layer is selected from one of ZnSe, ZnS and ZnSeS.

The quantum dot, wherein the partial size of the quantum dot is 4-8nm.Further, the quantum dot, wherein The quantum dot is blue light quantum point, and the partial size of the quantum dot core is 2-4nm, and the metallic element in the metal layer is selected from Zn。

Further, the quantum dot, wherein the quantum dot be red light quantum point or green light quantum point, it is described The partial size of quantum dot core is 4-6nm, and the metallic element in the metal layer is selected from Zn or Ga.

The quantum dot, wherein the quantum dot includes quantum dot core, coats the first metal of the quantum dot core Layer coats the first semiconductor shell of the first metal layer, coats the second metal layer of the first semiconductor shell, cladding Second semiconductor shell of the second metal layer；Wherein, the metallic element in the first metal layer and second metal Metallic element in layer is independently selected from one of Zn, Hg, Al, Ga and In or a variety of.

The quantum dot, wherein the material of the material of the first semiconductor shell and the second semiconductor shell Independently selected from Group II-VI semiconductor material.Further, the quantum dot, wherein the Group II-VI semiconductor material One in ZnSe, ZnS, ZnTe, ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, HgSeS, HgSeTe and HgSTe Kind.

The quantum dot, wherein the partial size of the quantum dot is 4-10nm.

A kind of preparation method of quantum dot, wherein include the following steps:

In the reaction system containing dispersing agent and solvent, make nonmetallic presoma and the first metal front precursor reactant forming amount Point core solution；

The second metal precursor is added into the quantum dot core solution, in quantum dot core forming metal layer on surface；

Semiconductor shell is formed in the layer on surface of metal；

Wherein, second metal precursor be selected from the presoma of Zn element, the presoma of Hg element, Al element presoma, One of presoma of the presoma of Ga element and In element is a variety of.

The preparation method of the quantum dot, wherein in the layer on surface of metal or the quantum dot core and metal layer Surface was formed in the step of semiconductor shell, and the material of the semiconductor shell is selected from Group II-VI semiconductor material.Further , the material of the semiconductor shell be selected from ZnSe, ZnS, ZnTe, ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, One of HgSeS, HgSeTe and HgSTe.

The preparation method of the quantum dot, wherein in the reaction system containing dispersing agent and solvent, make it is nonmetallic before In the step of driving body and the first metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is V group element Presoma, first metal precursor are the presoma of group-III element.Further, the presoma of the V group element is selected from One of presoma of the presoma of N element, the presoma of P element and As element is a variety of, the forerunner of the group-III element Body is selected from one or both of presoma and presoma of In element of Ga element.

The preparation method of the quantum dot, wherein in the reaction system containing dispersing agent and solvent, make it is nonmetallic before In the step of driving body and the first metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is V group element The presoma of presoma and VI race element, before first metal precursor is the presoma and II race element of group-III element Drive body.Further, the presoma of the V group element be selected from the presoma of N element, P element presoma and As element before Drive one of body or a variety of；The presoma of VI race element is selected from the presoma of Se element, the presoma of S element and Te member One of presoma of element is a variety of；Before the presoma of the group-III element is selected from the presoma and In element of Ga element Drive one or both of body；In the presoma of presoma and Hg element of the presoma of II race element selected from Zn element It is one or more.

The preparation method of the quantum dot, wherein in the reaction system containing dispersing agent and solvent, make it is nonmetallic before In the step of driving body and the first metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is selected from P element Presoma, first metal precursor are selected from one or both of presoma and presoma of In element of Ga element；To The second metal precursor is added in the quantum dot core solution, in quantum dot core forming metal layer on surface step, described second Metal precursor is selected from the presoma of Zn element or the presoma of Ga element.

The preparation method of the quantum dot, wherein in the reaction system containing dispersing agent and solvent, make it is nonmetallic before In the step of driving body and the first metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is before P element Drive the presoma and Se elemental precursor of body, S element；First metal precursor is the presoma and Zn member of group-III element The presoma of element, wherein the presoma of the group-III element is the presoma of In element or the presoma of the group-III element For the presoma of In element and the presoma of Ga element；The second metal precursor is added into the quantum dot core solution, is measuring In the step of son point core forming metal layer on surface, second metal precursor is selected from the presoma of Zn element.

The preparation method of the quantum dot, wherein in the reaction system containing dispersing agent and solvent, make it is nonmetallic before In the step of driving body and the first metal front precursor reactant forming amount sub- point core solution, the partial size for the quantum dot core being prepared is less than Equal to 4nm；The second metal precursor is added in the quantum dot core solution, the quantum dot core forming metal layer on surface the step of In, second metal precursor is selected from the presoma of Zn element or the presoma of Ga element, the presoma choosing of the Zn element From one of zinc iodide, zinc acetate and diethyl zinc or a variety of, the presoma of the Ga element be selected from gallium iodide, gallium chloride and One of acetic acid gallium is a variety of.

The preparation method of the quantum dot, wherein in the reaction system containing dispersing agent and solvent, make it is nonmetallic before In the step of driving body and the first metal front precursor reactant forming amount sub- point core solution, the partial size for the quantum dot core being prepared is greater than 4nm；The second metal precursor is added in the quantum dot core solution, in quantum dot core forming metal layer on surface, second gold medal Belong to presoma and be selected from the presoma of Zn element or the presoma of Ga element, the presoma of the Zn element be selected from zinc chloride and/or The presoma of zinc oxide, the Ga element is selected from gallium chloride and/or gallium oxide.

The preparation method of the quantum dot, wherein include the following steps:

The second metal precursor is added into the quantum dot core solution, forms the first metal layer on quantum dot core surface；

The first semiconductor shell is formed on the first metal layer surface；

Second metal layer is formed in the first semiconductor shell layer surface；

The second semiconductor shell is formed on the second metal layer surface；

Wherein, presoma independently selected from Zn element of the material of the first metal layer and the material of the second metal layer, The presoma of Hg element, the presoma of Al element, the presoma of Ga element and In element one of presoma or a variety of.

The preparation method of the quantum dot, wherein the material of the first semiconductor shell and the second semiconductor shell Material independently selected from Group II-VI semiconductor material.It is further preferred that the Group II-VI semiconductor material be selected from ZnSe, One of ZnS, ZnTe, ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, HgSeS, HgSeTe and HgSTe.

Preferably, the preparation method of the quantum dot makes nonmetallic in the reaction system containing dispersing agent and solvent In the step of presoma and the first metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is V group element Presoma, first metal precursor be group-III element presoma.It is further preferred that the forerunner of the V group element Body is selected from one of presoma of the presoma of N element, the presoma of P element and As element or a variety of, the group-III element Presoma be selected from the presoma and one or both of presoma of In element of Ga element.

Preferably, the preparation method of the quantum dot makes nonmetallic in the reaction system containing dispersing agent and solvent In the step of presoma and the first metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is V group element Presoma and VI race element presoma, first metal precursor is the presoma and II race element of group-III element Presoma.Further, the presoma of the V group element is selected from the presoma of N element, the presoma of P element and As element One of presoma is a variety of；The presoma of VI race element is selected from the presoma and Te of the presoma of Se element, S element One of presoma of element is a variety of；Presoma and In element of the presoma of the group-III element selected from Ga element One or both of presoma；In the presoma of presoma and Hg element of the presoma of II race element selected from Zn element It is one or more.

The utility model has the advantages that quantum dot provided by the invention includes quantum dot core, the quantum is coated or non-fully coated completely The metal layer of point core coats the semiconductor shell of the metal layer or the cladding metal layer and the quantum dot core, wherein institute The metallic element stated in metal layer is selected from one of Zn, Hg, Al, Ga and In or a variety of.The metal layer can be with quantum dot The ligand on core surface is bonded as connection tie with quantum dot nuclear phase, and quantum dot core surface active is promoted to become semiconductor shell The reaction center of further growth is conducive to further semiconductor shell growth response；Metal in the metal layer simultaneously Atom is formed by crystal structure by above-mentioned be bonded with quantum dot core, can effectively be passivated quantum dot core surface, reduce it Surface defect simultaneously reduces the lattice mismatch between nucleocapsid, to enhance the luminous efficiency and dimensional homogeneity of quanta point material；Packet The semiconductor shell overlayed on outside the metal layer effectively passive metal layer surface and can reduce its surface defect, while described Part metals atom in metal layer can also form crystal structure by chemical bonds with the anion on semiconductor shell, To reduce the crystal mismatch between quantum dot nucleocapsid, the luminous efficiency and dimensional homogeneity of quanta point material are further increased.

Detailed description of the invention

Fig. 1 is a kind of structural schematic diagram of specific embodiment of quantum dot of the present invention.

Fig. 2 is the structural schematic diagram of quantum dot another kind specific embodiment of the present invention.

Specific embodiment

The present invention provides a kind of quantum dots and preparation method thereof, to make the purpose of the present invention, technical solution and effect more Add clear, clear, the present invention is described in more detail below.It should be appreciated that specific embodiment described herein is only used To explain the present invention, it is not intended to limit the present invention.

As preparation cadmium-free quantum dots and cadmium content point used in presoma type and in terms of there are bright Significant difference is different, this makes cadmium-free quantum dots that can have more crystal defects and non-uniform in the formation of core-shell structure system Size distribution, the luminescent properties of cadmium content point material are lagged far behind so as to cause the luminescent properties of cadmium-free quantum dots material.

Quantum dot of the invention, wherein the quantum dot includes quantum dot core, coats or non-fully coat the amount completely The metal layer of son point core, coats the metal layer or coats the semiconductor shell of metal layer and the quantum dot core, wherein is described Metallic element in metal layer is selected from one of Zn, Hg, Al, Ga and In or a variety of.

It is different according to the dosage for the second metal precursor being added during the preparation process, one layer of packet completely can be prepared Cover or non-fully coat the metal layer of the quantum dot core.As shown in Figure 1, the quantum dot is radially from the inside to the outside successively Semiconductor shell including quantum dot core 10, the metal layer 20 of the cladding quantum dot core 10 and the cladding metal layer 20 30.The metal layer 20 is in the surface coated density of the quantum dot core 10, because before the second metal for being added during the preparation process It drives the dosage difference of body and has a certain difference, form the structure for being coated completely or non-fully coated by the metal layer, but Do not interfere the metal layer 20 in the formation on 10 surface of quantum dot core.

Preferably, the metal layer is coated on quantum dot core surface, and can be connection with the ligand on quantum dot core surface Tie is bonded with quantum dot nuclear phase, to activate the surface of quantum dot core, promotes the growth response of semiconductor shell；Meanwhile institute The metallic atom and quantum dot core stated in metal layer pass through the above-mentioned crystal structure bonded together to form, can effectively be passivated quantum dot core To reduce its surface defect, the crystal structure can also effectively reduce the crystalline substance between quantum dot core and semiconductor shell on surface Lattice mismatch, to promote the luminous efficiency and dimensional homogeneity of quantum dot.

Preferably, the material of the quantum dot core is III-V group semi-conductor material or III-V group semi-conductor material and II- Alloy semiconductor material composed by VI race semiconductor material；It is further preferred that the material of the quantum dot core is iii-v Semiconductor material, the III-V group semi-conductor material be selected from GaN, GaP, GaAs, InP, InAs, InAsP, GaAsP, InGaP, One of InGaAs, InGaAsP etc., but not limited to this；It is further preferred that the material of the quantum dot core is iii-v Alloy semiconductor material composed by semiconductor material and Group II-VI semiconductor material, the III-V group semi-conductor material are selected from One of GaN, GaP, GaAs, InP, InAs, InAsP, GaAsP, InGaP, InGaAs, InGaAsP etc., the II-VI group Semiconductor material be selected from ZnSe, ZnS, ZnTe, ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, HgSeS, HgSeTe and One of HgSTe.As preferred citing, the alloy semiconductor material is InPZnS, InPZnSe, InPZnSeS, One of InGaPZnSe, InGaPZnS and InGaPZnSeS etc., but not limited to this.

Preferably, the material of the semiconductor shell is Group II-VI semiconductor material.It is further preferred that described partly lead The Group II-VI semiconductor material of body shell layer be selected from ZnSe, ZnS, ZnTe, ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, One of HgSeS, HgSeTe and HgSTe.

Preferably, the glow peak wave-length coverage of the quantum dot is 400-700 nanometers.

Preferably, the peak width at half height range of the glow peak of the quantum dot is 20-100 nanometers.

In a preferred embodiment, the material of the quantum dot core is in InP or InGaP, the metal layer Metallic element be selected from Zn or Ga；Due to Zn the Ga atom in metal layer have with the InP or InGaP of quantum dot core compared with For matched element size and lattice parameter, and stronger with the binding ability of quantum dot core, therefore being capable of effectively passivated surface And reduce lattice mismatch.

It is further preferred that the quantum dot, wherein the material of the semiconductor shells layer be selected from ZnSe, ZnS and One of ZnSeS.At this point, forming the reactivity of precursor reagent and the reacting for the metal layer of semiconductor shells layer Active matching is more preferable, can achieve the effect that more effectively to react activation.

In a preferred embodiment, the material of the quantum dot core is III-V group semi-conductor material and II-VI group Alloy semiconductor material composed by semiconductor material, the metallic element in the metal layer are selected from Zn.Due in metal layer Zn atom has alloy semiconductor composed by III-V group semi-conductor material and Group II-VI semiconductor material with quantum dot core The more matched element size of material and lattice parameter, and it is stronger with the binding ability of quantum dot core, therefore can be effectively blunt Change surface and reduces lattice mismatch.

It is further preferred that the quantum dot, wherein the III-V group semi-conductor material and II-VI group semiconductor material Expect composed by alloy semiconductor material be selected from InPZnS, InPZnSe, InPZnSeS, InGaPZnSe, InGaPZnS and One of InGaPZnSeS.

Still more preferably, the quantum dot, wherein the material of the semiconductor shells layer be selected from ZnSe, ZnS and One of ZnSeS.At this point, forming the reactivity of precursor reagent and the reacting for the metal layer of semiconductor shells layer Active matching is more preferable, can achieve the effect that more effectively to react activation.

In a preferred embodiment, the partial size of the quantum dot is that 4-8nm is easy to cause when partial size is too big Quantum dot internal stress is too big, makes chemical bond rupture in crystal, forms lattice defect, influences to shine.

It is further preferred that the quantum dot is blue light quantum point, the partial size of the quantum dot core is 2-4nm, the gold The metallic element belonged in layer is selected from Zn or Ga.Precursor reagent due to forming metal layer has high reactivity, uses These precursor reagents can also increase the growth rate of semiconductor shells layer while generating metal layer, to give birth to rapidly At semiconductor shells layer, effectively inhibit quantum dot core grow up and corresponding red shift of wavelength.

It is another it is further preferred that the quantum dot be red light quantum point or green light quantum point, the quantum dot core Partial size is 4-6nm, and the metallic element in the metal layer is selected from Zn or Ga.Precursor reagent due to forming metal layer has Low reactivity, using these precursor reagents while generating metal layer can also slowing down outer shell life Long rate, to allow quantum dot core to there is the sufficient time to grow up and realize corresponding red shift of wavelength to green or red band.

In a preferred embodiment, quantum dot of the invention, wherein the quantum dot includes quantum dot core, packet The first metal layer for covering the quantum dot core coats the first semiconductor shell of the first metal layer, further includes coating completely The second metal layer of the first semiconductor shell coats the second semiconductor shell of the second metal layer；Wherein, described The metallic element in metallic element and second metal layer in one metal layer is independently selected from one of Zn, Hg, Al, Ga and In Or it is a variety of.

The metallic element in metallic element and second metal layer in the first metal layer independently selected from Zn, Hg, Al, One of Ga and In or a variety of, that is to say, that the first metal layer is identical with material ranges selected by second metal layer. It should be noted that the first metal layer and the second metal layer can select identical material in above-mentioned material range, Material different in above-mentioned material range can be selected.

It is different according to the dosage for the second metal precursor being added during the preparation process, it can be prepared the quantum Point core coats completely or non-fully coats the first metal layer.Likewise, according to the second metal front being added during the preparation process The dosage of body is different, and the second metal that the first semiconductor shell is coated completely or non-fully coated can be prepared Layer.As shown in Fig. 2, the quantum dot radially successively includes quantum dot core 10, the cladding quantum dot core from the inside to the outside 10 the first metal layer 20 and the first semiconductor shell 30, cladding first semiconductor of the cladding the first metal layer 20 The second metal layer 40 of shell 30 and the second semiconductor shell 50 of the cladding second metal layer 40.The first metal layer 20 in the surface coated density of the quantum dot core 10, because the dosage for the second metal precursor being added during the preparation process is different And it has a certain difference, but do not interfere the first metal layer 20 in the formation on 10 surface of quantum dot core.Described second Metal layer 40 is in the surface coated density of the first semiconductor shell 30, because of the second metal front being added during the preparation process The dosage of body is different and has a certain difference, but does not interfere the second metal layer 40 in 30 table of the first semiconductor shell The formation in face.

Preferably, the first metal layer is coated on quantum dot core surface, and can be with the ligand on quantum dot core surface Connection tie is bonded with quantum dot nuclear phase, to activate the surface of quantum dot core, promotes the growth response of the first semiconductor shell； Meanwhile the metallic atom in the first metal layer can bond together to form crystal structure, the crystalline substance by above-mentioned with quantum dot core Body structure can be passivated quantum dot core surface effectively to reduce its surface defect, and the crystal structure can also the amount of effectively reducing Lattice mismatch between son point core and the first semiconductor shell, to promote the luminous efficiency and dimensional homogeneity of quantum dot.Into One step, the second metal layer is coated on outside the first semiconductor shell, and can effectively be passivated the first semiconductor shell table Face enhances the luminous efficiency of quantum dot to reduce its surface defect, and the metallic atom in the second metal layer can also It is enough to pass through chemical bonded refractory with the anion of the first semiconductor shell outer surface and the anion of the second semiconductor shell inner surface Conjunction forms crystal structure, and the crystal structure can further reduce the lattice mismatch between quantum dot nucleocapsid, thus into one Step ground promotes the luminous efficiency and dimensional homogeneity of quantum dot.

Preferably, the material of the material of the first semiconductor shell and the second semiconductor shell independently selected from Group II-VI semiconductor material.It is further preferred that the Group II-VI semiconductor material be selected from ZnSe, ZnS, ZnTe, ZnSeS, One of ZnSeTe, ZnSTe, HgSe, HgS, HgTe, HgSeS, HgSeTe and HgSTe.That is, described the first half lead Body shell layer is identical as material ranges selected by the second semiconductor shell.It should be noted that the first semiconductor shell Selected Group II-VI semiconductor material can phase with Group II-VI semiconductor material selected by the second semiconductor shell Together, it can also be different.

Preferably, the partial size of the quantum dot is 4-10nm, and selecting the particle size is easy to cause since partial size is too big Quantum dot internal stress is too big, makes chemical bond rupture in crystal, forms lattice defect, influences to shine.

Preferably, the material of the quantum dot core is selected from InP or InGaP, the first metal layer and second metal Metallic element in layer is selected from Zn or Ga；It is further preferred that the quantum dot, wherein the first semiconductor shell The material of material and the second semiconductor shell is independently selected from one of ZnSe, ZnS and ZnSeS.

Preferably, the material of the quantum dot core is made of III-V group semi-conductor material and Group II-VI semiconductor material Alloy semiconductor material, the metallic element in the first metal layer and the second metal layer is selected from Zn.Further preferably , the quantum dot, wherein alloy composed by the III-V group semi-conductor material and Group II-VI semiconductor material is partly led Body material is selected from one of InPZnS, InPZnSe, InPZnSeS, InGaPZnSe, InGaPZnS and InGaPZnSeS.Into one Step is preferred, the quantum dot, wherein the material of the material of the first semiconductor shell and the second semiconductor shell is independent Ground is selected from one of ZnSe, ZnS and ZnSeS.

Preferably, the partial size of the quantum dot is that 4-8nm is easy to cause quantum dot internal stress too big when partial size is too big, Make chemical bond rupture in crystal, forms lattice defect, influence to shine.It is further preferred that the quantum dot is blue light quantum point, The partial size of the quantum dot core is 2-4nm, and the metallic element in the first metal layer and second metal layer is selected from Zn or Ga.It is excellent Choosing, the quantum dot is red light quantum point or green light quantum point, and the partial size of the quantum dot core is 4-6nm, described first Metallic element in metal layer and second metal layer is selected from Zn or Ga.

The present invention also provides a kind of preparation methods of quantum dot, include the following steps:

Semiconductor shell is formed in the layer on surface of metal；

The quantum dot being prepared using the method for the invention is formed on quantum dot core surface and coats the quantum dot core Metal layer, the metal layer can with the ligand on quantum dot core surface be connection tie be bonded with quantum dot nuclear phase, thus work Change the surface of quantum dot core, promotes the growth response of semiconductor shell；Meanwhile metallic atom and quantum dot in the metal layer Core can be passivated quantum dot core surface effectively to reduce its surface defect by the above-mentioned crystal structure bonded together to form, described The lattice that crystal structure can also effectively reduce between quantum dot core and semiconductor shell is adapted to, to promote shining for quantum dot Efficiency and dimensional homogeneity.

Preferably, the preparation method of the quantum dot, in the layer on surface of metal or the quantum dot core and metal Layer surface was formed in the step of semiconductor shell, and the material of the semiconductor shell is selected from Group II-VI semiconductor material.Further Preferably, the material of the semiconductor shell is selected from one of ZnSe, ZnS and ZnSeS.

Preferably, the preparation method of the quantum dot forms nonmetallic presoma and the first metal front precursor reactant In the step of quantum dot core solution, the nonmetallic presoma is the presoma of V group element, and first metal precursor is The presoma of group-III element.

Specifically, the presoma of the group-III element includes: aluminum phosphate (aluminum phosphate), aluminum acetate (aluminum acetate), aluminium acetylacetonate (aluminum acetylacetonate), silver iodide (aluminum Iodide), aluminium bromide (aluminum bromide), aluminium chloride (aluminum chloride), aluminum fluoride (aluminum Fluoride), aluminium carbonate (aluminum carbonate), cyaniding aluminium (aluminum cyanide), aluminum nitrate (aluminum Nitrate), aluminium oxide (aluminum oxide), peroxidating aluminium (aluminum peroxide), aluminum sulfate (aluminum Sulfate), aluminum oleate (aluminum oleate), aluminum stearate (aluminum stearate), tetradecanoic acid aluminium (aluminum myristate), aluminum palmitate (aluminum palmitate), phosphoric acid gallium (gallium Phosphate), acetic acid gallium (gallium acetate), acetylacetone,2,4-pentanedione gallium (gallium acetylacetonate), gallium iodide (gallium iodide), gallium bromide (gallium bromide), gallium chloride (gallium chloride), gallium fluoride (gallium fluoride), carbonic acid gallium (gallium carbonate), cyaniding gallium (gallium cyanide), gallium nitrate (gallium nitrate), gallium oxide (gallium oxide), peroxidating gallium (gallium peroxide), gallium sulfate (gallium sulfate), oleic acid gallium (gallium oleate), stearic acid gallium (gallium stearate), tetradecanoic acid Gallium (gallium myristate), hexadecanoic acid gallium (gallium palmitate), indium phosphate (indium phosphate), Indium acetate (indium acetate), Indium Tris acetylacetonate (indium acetylacetonate), indium iodide (indium Iodide), indium bromide (indium bromide), inidum chloride (indium chloride), indium (indium Fluoride), carbonic acid indium (indium carbonate), cyaniding indium (indium cyanide), indium nitrate (indium Nitrate), indium oxide (indium oxide), peroxidating indium (indium peroxide), indium sulfate (indium Sulfate), oleic acid indium (indium oleate), stearic acid indium (indium stearate), tetradecanoic acid indium (indium Myristate), at least one of hexadecanoic acid indium (indium palmitate) etc., but not limited to this.

Specifically, the presoma of the V group element includes: tris-trimethylsilyl phosphine, alkyl Phosphines (such as triethyl phosphine, tributyl phosphine, trioctyl phosphine, Triphenyl phosphine, tricyclohexyl phosphine), arsenic iodide (aluminum iodide), arsenic bromide (aluminum bromide), arsenic chloride (arsenic chloride), arsenic oxide arsenoxide (aluminum oxide), arsenic sulfate (aluminum sulfate), nitric oxide (nitric oxide), nitric acid (nitric acid), ammonium nitrate (ammonium At least one of nitrate) etc., but not limited to this.

It is further preferred that the presoma of the V group element is selected from the presoma of N element, the presoma of P element and As member One of presoma of element is a variety of, before the presoma of the group-III element is selected from the presoma and In element of Ga element Drive one or both of body.

Specifically, the presoma of the N element includes: nitric oxide (nitric oxide), nitric acid (nitric acid) At least one of with ammonium nitrate (ammonium nitrate) etc., but not limited to this.The presoma of the P element includes three (trimethyl silicon substrate) phosphate (tris(trimethylsilyl) phosphine) or alkyl phosphine compound (alkyl Phosphines) (such as triethyl phosphine (triethyl phosphine), tributyl phosphorus (tributyl phosphine), three N-octyl phosphorus (trioctyl phosphine), triphenylphosphine (triphenyl phosphine) and tricyclohexyl phosphine (tricyclohexyl phosphine)), but not limited to this.The presoma of the As element includes arsenic iodide (aluminum Iodide), arsenic bromide (aluminum bromide), arsenic chloride (arsenic chloride), arsenic oxide arsenoxide (aluminum Oxide) and at least one of arsenic sulfate (aluminum sulfate) etc., but not limited to this.

Specifically, the presoma of the Ga element includes: phosphoric acid gallium (gallium phosphate), acetic acid gallium (gallium acetate), acetylacetone,2,4-pentanedione gallium (gallium acetylacetonate), gallium iodide (gallium iodide), Gallium bromide (gallium bromide), gallium chloride (gallium chloride), gallium fluoride (gallium fluoride), carbon Sour gallium (gallium carbonate), cyaniding gallium (gallium cyanide), gallium nitrate (gallium nitrate), oxidation Gallium (gallium oxide), peroxidating gallium (gallium peroxide), gallium sulfate (gallium sulfate), oleic acid gallium (gallium oleate), stearic acid gallium (gallium stearate), tetradecanoic acid gallium (gallium myristate) and ten Six alkanoic acid galliums (gallium palmitate), but not limited to this.The presoma of the In element includes indium phosphate (indium Phosphate), indium acetate (indium acetate), Indium Tris acetylacetonate (indium acetylacetonate), indium iodide (indium iodide), indium bromide (indium bromide), inidum chloride (indium chloride), indium (indium Fluoride), carbonic acid indium (indium carbonate), cyaniding indium (indium cyanide), indium nitrate (indium Nitrate), indium oxide (indium oxide), peroxidating indium (indium peroxide), indium sulfate (indium Sulfate), oleic acid indium (indium oleate), stearic acid indium (indium stearate), tetradecanoic acid indium (indium Myristate), at least one of hexadecanoic acid indium (indium palmitate) etc., but not limited to this.

Preferably, the preparation method of the quantum dot forms nonmetallic presoma and the first metal front precursor reactant In the step of quantum dot core solution, the nonmetallic presoma be V group element presoma and VI race element presoma, it is described First metal precursor is the presoma of group-III element and the presoma of II race element.

Specifically, the presoma of VI race element includes: that Te, Se, S element and some organic matters are formed by chemical combination Object, specially Se-TOP, Se-TBP, Se-TPP, Se-ODE, Se-OA (selenium-oleic acid), Se-ODA (selenium-octadecylamine)、Se-TOA (selenium-trioctylamine)、Se-ODPA (selenium- octadecylphosphonic acid)、Se-OLA (selenium-oleylamine)、Se-OCA (selenium- octylamine)、Te-TOP、Te-TBP、Te-TPP、Te-ODE、Te-OA、Te-ODA、Te-TOA、Te-ODPA、Te-OLA、 Te-OCA, S-TOP, S-TBP, S-TPP, S-ODE, S-OA, S-ODA, S-TOA, S-ODPA, S-OLA, S-OCA, alkyl hydrosulfide (such as hexyl mercaptan (hexanethiol), spicy thioalcohol (octanethiol), decyl mercaptan (decanethiol), lauryl mercaptan (dodecanethiol) and hexadecyl mercaptan (hexadecanethiol)), mercapto propyl silane At least one of (mercaptopropylsilane) etc., but not limited to this.

Specifically, the presoma of II race element includes: zinc methide (dimethyl Zinc), diethyl zinc (diethyl Zinc), zinc acetate (Zinc acetate), zinc acetylacetonate (Zinc acetylacetonate), zinc iodide (Zinc iodide), zinc bromide (Zinc bromide), zinc chloride (Zinc chloride), zinc fluoride (Zinc Fluoride), zinc carbonate (Zinc carbonate), zinc cyanide (Zinc cyanide), zinc nitrate (Zinc nitrate), oxygen Change zinc (Zinc oxide), zinc peroxide (Zinc peroxide), zinc perchlorate (Zinc perchlorate), zinc sulfate (Zinc sulfate), zinc oleate (Zinc oleate), zinc stearate (Zinc stearate), dimethylmercury (dimethyl Mercury), dimethylmercury (diethyl mercury), mercuric acetate (mercury acetate), acetylacetone,2,4-pentanedione mercury (mercury Acetylacetonate), mercuric iodixde (mercury iodide), mercuric bromide (mercury bromide), mercury chloride (mercury chloride), mercuric fluoride (mercury fluoride), carbonic acid mercury (mercury carbonate), mercuric nitrate (mercury nitrate), mercury oxide (mercury oxide), mercuric perchlorate (mercury perchlorate), mercuric phosphate (mercury phosphide), mercuric sulfate (mercury sulfate), mercuric oleate (mercury oleate) and mercuric stearte It is one of (mercury stearate) or a variety of, but not limited to this.

It is further preferred that the preparation method of the quantum dot, before the presoma of the V group element is selected from N element Drive one of presoma of body, the presoma of P element and As element or a variety of；The presoma of VI race element is selected from Se member One of presoma of the presoma of element, the presoma of S element and Te element is a variety of；The presoma of the group-III element One or both of presoma and the presoma of In element selected from Ga element；The presoma of II race element is selected from Zn member One of plain presoma of presoma and Hg element is a variety of.

The presoma of the Se element is that Se element and some organic matters are formed by compound, specifically, the Se is first The presoma of element includes Se-TOP, Se-TBP, Se-TPP, Se-ODE, Se-OA (selenium-oleic acid), Se-ODA (selenium-octadecylamine)、Se-TOA (selenium-trioctylamine)、Se-ODPA (selenium- octadecylphosphonic acid)、Se-OLA (selenium-oleylamine)、Se-OCA (selenium- At least one of octylamine) etc., but not limited to this.The presoma of the S element is S element and some organic matter institutes The compound of formation, specifically, the presoma of the S element include S-TOP, S-TBP, S-TPP, S-ODE, S-OA, S-ODA, S-TOA, S-ODPA, S-OLA, S-OCA, alkyl hydrosulfide (such as hexyl mercaptan (hexanethiol), spicy thioalcohol (octanethiol), decyl mercaptan (decanethiol), lauryl mercaptan (dodecanethiol) and hexadecyl mercaptan At least one of (hexadecanethiol)), mercapto propyl silane (mercaptopropylsilane)) etc., but be not limited to This.The presoma of the Te element is that Te element and some organic matters are formed by compound, specifically, before the Te element Driving body includes Te-TOP, Te-TBP, Te-TPP, Te-ODE, Te-OA, Te-ODA, Te-TOA, Te-ODPA, Te-OLA, Te-OCA At least one of Deng, but not limited to this.

The presoma of the Zn element include zinc methide (dimethyl Zinc), diethyl zinc (diethyl Zinc), Zinc acetate (Zinc acetate), zinc acetylacetonate (Zinc acetylacetonate), zinc iodide (Zinc iodide), bromine Change zinc (Zinc bromide), zinc chloride (Zinc chloride), zinc fluoride (Zinc fluoride), zinc carbonate (Zinc Carbonate), zinc cyanide (Zinc cyanide), zinc nitrate (Zinc nitrate), zinc oxide (Zinc oxide), peroxide Change zinc (Zinc peroxide), zinc perchlorate (Zinc perchlorate), zinc sulfate (Zinc sulfate), zinc oleate At least one of (Zinc oleate), zinc stearate (Zinc stearate) etc., but not limited to this.Before the Hg element Driving body includes dimethylmercury (dimethyl mercury), dimethylmercury (diethyl mercury), mercuric acetate (mercury Acetate), acetylacetone,2,4-pentanedione mercury (mercury acetylacetonate), mercuric iodixde (mercury iodide), mercuric bromide (mercury bromide), mercury chloride (mercury chloride), mercuric fluoride (mercury fluoride), carbonic acid mercury (mercury carbonate), mercuric nitrate (mercury nitrate), mercury oxide (mercury oxide), mercuric perchlorate (mercury perchlorate), mercuric phosphate (mercury phosphide), mercuric sulfate (mercury sulfate), oleic acid At least one of mercury (mercury oleate) and mercuric stearte (mercury stearate) etc., but not limited to this.

In a preferred embodiment, the preparation method of the quantum dot makes nonmetallic presoma and the first gold medal In the step of belonging to forerunner's precursor reactant forming amount point core solution, the nonmetallic presoma is selected from the presoma of P element, and described the One metal precursor is selected from one or both of presoma and presoma of In element of Ga element；It is molten to the quantum dot core The second metal precursor is added in liquid, in quantum dot core forming metal layer on surface step, second metal precursor is selected from The presoma of Zn element or the presoma of Ga element.

Specifically, the presoma of the P element includes: three (trimethyl silicon substrate) phosphate (tris (trimethylsilyl) phosphine) or alkyl phosphine compound (alkyl phosphines) (such as triethyl phosphine (triethyl phosphine), tributyl phosphorus (tributyl phosphine), three n-octyl phosphorus (trioctyl Phosphine), triphenylphosphine (triphenyl phosphine) and tricyclohexyl phosphine (tricyclohexyl Phosphine)), but not limited to this.

Specifically, the presoma of the Zn element includes: zinc methide (dimethyl Zinc), diethyl zinc (diethyl Zinc), zinc acetate (Zinc acetate), zinc acetylacetonate (Zinc acetylacetonate), zinc iodide (Zinc iodide), zinc bromide (Zinc bromide), zinc chloride (Zinc chloride), zinc fluoride (Zinc Fluoride), zinc carbonate (Zinc carbonate), zinc cyanide (Zinc cyanide), zinc nitrate (Zinc nitrate), oxygen Change zinc (Zinc oxide), zinc peroxide (Zinc peroxide), zinc perchlorate (Zinc perchlorate), zinc sulfate At least one of (Zinc sulfate), zinc oleate (Zinc oleate), zinc stearate (Zinc stearate) etc., but not It is limited to this.

In a preferred embodiment, the preparation method of the quantum dot makes nonmetallic presoma and first In the step of metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is presoma, the S element of P element Presoma and Se elemental precursor；First metal precursor be group-III element presoma and Zn element presoma, Wherein the presoma of the group-III element is the presoma of In element or before the presoma of the group-III element is In element Drive the presoma of body and Ga element；The second metal precursor is added into the quantum dot core solution, in quantum dot core surface shape At in metal layer step, second metal precursor is selected from the presoma of Zn element.

Specifically, the presoma of the P element includes: three (trimethyl silicon substrate) phosphate (tris (trimethylsilyl) phosphine) or alkyl phosphine compound (alkyl phosphines) (such as triethyl phosphine (triethyl phosphine), tributyl phosphorus (tributyl phosphine), three n-octyl phosphorus (trioctyl Phosphine), triphenylphosphine (triphenyl phosphine) and tricyclohexyl phosphine (tricyclohexyl Phosphine)), but not limited to this.The presoma of the S element is that S element and some organic matters are formed by compound, is had Body, the presoma of the S element includes S-TOP, S-TBP, S-TPP, S-ODE, S-OA, S-ODA, S-TOA, S-ODPA, S- OLA, S-OCA, alkyl hydrosulfide (such as hexyl mercaptan (hexanethiol), spicy thioalcohol (octanethiol), decyl mercaptan (decanethiol), lauryl mercaptan (dodecanethiol) and hexadecyl mercaptan (hexadecanethiol)), mercapto At least one of propyl silane (mercaptopropylsilane)) etc., but not limited to this.The presoma of the Se element is Se element and some organic matters are formed by compound, specifically, the presoma of the Se element include Se-TOP, Se-TBP, Se-TPP、Se-ODE、Se-OA (selenium-oleic acid)、Se-ODA (selenium-octadecylamine)、 Se-TOA (selenium-trioctylamine)、Se-ODPA (selenium-octadecylphosphonic acid)、 At least one of Se-OLA (selenium-oleylamine), Se-OCA (selenium-octylamine) etc., but not It is limited to this.

Specifically, the presoma of the Zn element includes: zinc methide (dimethyl Zinc), diethyl zinc (diethyl Zinc), zinc acetate (Zinc acetate), zinc acetylacetonate (Zinc acetylacetonate), zinc iodide (Zinc iodide), zinc bromide (Zinc bromide), zinc chloride (Zinc chloride), zinc fluoride (Zinc Fluoride), zinc carbonate (Zinc carbonate), zinc cyanide (Zinc cyanide), zinc nitrate (Zinc nitrate), oxygen Change zinc (Zinc oxide), zinc peroxide (Zinc peroxide), zinc perchlorate (Zinc perchlorate), zinc sulfate At least one of (Zinc sulfate), zinc oleate (Zinc oleate), zinc stearate (Zinc stearate) etc., but not It is limited to this.The presoma of the In element include indium phosphate (indium phosphate), indium acetate (indium acetate), Indium Tris acetylacetonate (indium acetylacetonate), indium iodide (indium iodide), indium bromide (indium Bromide), inidum chloride (indium chloride), indium (indium fluoride), carbonic acid indium (indium Carbonate), cyaniding indium (indium cyanide), indium nitrate (indium nitrate), indium oxide (indium Oxide), peroxidating indium (indium peroxide), indium sulfate (indium sulfate), oleic acid indium (indium Oleate), stearic acid indium (indium stearate), tetradecanoic acid indium (indium myristate), hexadecanoic acid indium At least one of (indium palmitate) etc., but not limited to this.The presoma of the Ga element includes phosphoric acid gallium (gallium phosphate), acetic acid gallium (gallium acetate), acetylacetone,2,4-pentanedione gallium (gallium Acetylacetonate), gallium iodide (gallium iodide), gallium bromide (gallium bromide), gallium chloride (gallium chloride), gallium fluoride (gallium fluoride), carbonic acid gallium (gallium carbonate), cyaniding gallium (gallium cyanide), gallium nitrate (gallium nitrate), gallium oxide (gallium oxide), peroxidating gallium (gallium peroxide), gallium sulfate (gallium sulfate), oleic acid gallium (gallium oleate), stearic acid gallium (gallium stearate), tetradecanoic acid gallium (gallium myristate) and hexadecanoic acid gallium (gallium Palmitate), but not limited to this.

In a preferred embodiment, the preparation method of the quantum dot makes nonmetallic presoma and the first gold medal In the step of belonging to forerunner's precursor reactant forming amount point core solution, the partial size for the quantum dot core being prepared is less than or equal to 4nm；It is described The second metal precursor is added in quantum dot core solution, the quantum dot core forming metal layer on surface the step of in, second gold medal Belong to presoma and be selected from the presoma of Zn element or the presoma of Ga element, the presoma of the Zn element is selected from zinc iodide, acetic acid One of zinc and diethyl zinc are a variety of, the presoma of the Ga element be selected from gallium iodide, gallium chloride and acetic acid gallium it is a kind of or It is a variety of.

In a preferred embodiment, the preparation method of the quantum dot makes nonmetallic presoma and the first gold medal In the step of belonging to forerunner's precursor reactant forming amount point core solution, the partial size for the quantum dot core being prepared is greater than 4nm；The quantum The second metal precursor is added in point core solution, the quantum dot core forming metal layer on surface the step of in, before second metal It drives body and is selected from the presoma of Zn element or the presoma of Ga element, the presoma of the Zn element is selected from zinc chloride and/or oxidation The presoma of zinc, the Ga element is selected from gallium chloride and/or gallium oxide.

In a preferred embodiment, the preparation method of the quantum dot, includes the following steps:

The first semiconductor shell is formed on the first metal layer surface；

The second metal precursor is added into the quantum dot solution, forms the second metal in the first semiconductor shell layer surface Layer；

The second semiconductor shell is formed on the second metal layer surface；

Wherein, presoma, Hg independently selected from Zn element of the material of the second metal layer and second metal precursor The presoma of element, the presoma of Al element, the presoma of Ga element and In element one of presoma or a variety of.It is described Presoma independently selected from Zn element of the material of second metal layer and second metal precursor, Hg element presoma, One of presoma of the presoma of Al element, the presoma of Ga element and In element is a variety of, that is to say, that described second Metal layer is identical with material ranges selected by the first metal layer.It should be noted that the second metal layer and first gold medal Identical material in above-mentioned material range can be selected by belonging to layer, can also select material different in above-mentioned material range.

The quantum dot being prepared using the method for the invention is formed on quantum dot core surface and coats the quantum dot core The first metal layer, the first metal layer can be connection tie and quantum dot nuclear phase key with the ligand on quantum dot core surface It closes, to activate the surface of quantum dot core, promotes the growth response of the first semiconductor shell；Meanwhile the gold in the metal layer Belong to atom and quantum dot core by the above-mentioned crystal structure bonded together to form, quantum dot core surface can be passivated effectively to reduce it Surface defect, the crystal structure can also effectively reduce the lattice mismatch between quantum dot core and the first semiconductor shell, from And promote the luminous efficiency and dimensional homogeneity of quantum dot.Further, it is formed described in cladding outside the first semiconductor shell The second metal layer of first semiconductor shell, the second metal layer can be passivated the first semiconductor shell layer surface effectively to subtract Its few surface defect, and then enhance the luminous efficiency of quantum dot, the metallic atom in the second metal layer can also be with first Semiconductor shell and the second semiconductor shell bond together to form crystal structure by above-mentioned, and the crystal structure can be further The lattice adaptation between quantum dot nucleocapsid is reduced, to further promote the luminous efficiency and dimensional homogeneity of quantum dot.

Preferably, the preparation method of the quantum dot forms the first semiconductor shell on the first metal layer surface The step of in, the material of the first semiconductor shell is selected from Group II-VI semiconductor material.It is further preferred that described first The Group II-VI semiconductor material of semiconductor shell is selected from one of ZnSe, ZnS and ZnSeS.

Preferably, the preparation method of the quantum dot forms the second semiconductor shell on the second metal layer surface The step of in, the material of the second semiconductor shell is selected from Group II-VI semiconductor material.It is further preferred that described second The Group II-VI semiconductor material of semiconductor shell is selected from one of ZnSe, ZnS and ZnSeS.That is, described the first half Conductor shell is identical as material ranges selected by the second semiconductor shell.It should be noted that first semiconductor shell Group II-VI semiconductor material selected by Group II-VI semiconductor material selected by layer and the second semiconductor shell can be with It is identical, it can also be different.

Preferably, the preparation method of the quantum dot makes nonmetallic in the reaction system containing dispersing agent and solvent In the step of presoma and the first metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is V group element Presoma, first metal precursor be group-III element presoma.The presoma of the specific V group element and described The type of III group semiconductor precursors is hereinbefore documented, and details are not described herein.It is further preferred that the V The presoma of race's element is selected from one of presoma of the presoma of N element, the presoma of P element and As element or a variety of, The presoma of the group-III element is selected from one or both of presoma and presoma of In element of Ga element.Specific institute State the presoma of the presoma of N element, the presoma of P element, the presoma of As element, the presoma of Ga element and In element Type is hereinbefore documented, and details are not described herein.

Preferably, the preparation method of the quantum dot makes nonmetallic in the reaction system containing dispersing agent and solvent In the step of presoma and the first metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is V group element Presoma and VI race element presoma, first metal precursor is the presoma and II race element of group-III element Presoma.The specific presoma of the V group element, the presoma of VI race element, the presoma of group-III element and II race element The type of presoma is hereinbefore documented, and details are not described herein.It is further preferred that the preparation side of the quantum dot Method, the presoma of the V group element are selected from one of the presoma of N element, the presoma of P element and presoma of As element Or it is a variety of；In presoma, the presoma of S element and the presoma of Te element of the presoma of VI race element selected from Se element It is one or more；The presoma of the group-III element is selected from one of presoma and presoma of In element of Ga element Or two kinds；The presoma of II race element is selected from one of the presoma of Zn element and the presoma of Hg element or a variety of. The selection of presoma is hereinbefore documented, and details are not described herein.

In a preferred embodiment, the preparation method of the quantum dot makes nonmetallic presoma and the first gold medal In the step of belonging to forerunner's precursor reactant forming amount point core solution, the nonmetallic presoma is selected from the presoma of P element, and described the One metal precursor is selected from one or both of presoma and presoma of In element of Ga element；In quantum dot core surface shape It is neutralized in the step of outer shell layer surface forms the first metal layer at the step of metal layer, second metal precursor is selected from Zn The presoma of element or the presoma of Ga element.The selection of presoma is hereinbefore documented, and details are not described herein.

In a preferred embodiment, the preparation method of the quantum dot makes nonmetallic presoma and first In the step of metal front precursor reactant forming amount sub- point core solution, the nonmetallic presoma is presoma, the S element of P element Presoma and Se elemental precursor；First metal precursor be group-III element presoma and Zn element presoma, Wherein the presoma of the group-III element is the presoma of In element or before the presoma of the group-III element is In element Drive the presoma of body and Ga element；Shell layer surface forms the first gold medal in the quantum dot core forming metal layer on surface the step of and outside In the step of belonging to layer, second metal precursor is selected from the presoma of Zn element.The selection of presoma hereinbefore has in detail It records, details are not described herein.

In a preferred embodiment, the preparation method of the quantum dot, anti-containing dispersing agent and solvent In the step of answering in system, making nonmetallic presoma and the first metal front precursor reactant forming amount sub- point core solution, it is prepared Quantum dot core partial size be less than or equal to 4nm；In the step of quantum dot core surface forms the first metal layer and in the first shell Layer surface was formed in the step of second metal layer, before second metal precursor is selected from the presoma or Ga element of Zn element Body is driven, the presoma of the Zn element is selected from one of zinc iodide, zinc acetate and diethyl zinc or a variety of, the Ga element It is one or more that presoma is selected from gallium iodide, gallium chloride and acetic acid gallium.

In a preferred embodiment, the preparation method of the quantum dot, anti-containing dispersing agent and solvent In the step of answering in system, making nonmetallic presoma and the first metal front precursor reactant forming amount sub- point core solution, it is prepared Quantum dot core partial size be greater than 4nm；In the step of quantum dot core surface forms the first metal layer and in the first outer shell table Face was formed in the step of second metal layer, and second metal precursor is selected from the presoma of Zn element or the forerunner of Ga element Body, the presoma of the Zn element are selected from zinc chloride and/or zinc oxide, the presoma of the Ga element be selected from gallium chloride and/or Gallium oxide.

The present invention also provides a kind of applications of quanta point material, wherein uses the quanta point material as functional material In preparing semiconductor devices.The semiconductor devices is electroluminescent device, photo luminescent devices, solar battery, display Any one in part, photodetector, bioprobe and device for non-linear optical.

By taking electroluminescent device as an example, quanta point material provided by the invention is used to prepare shining for electroluminescent device Layer, obtained quanta point electroluminescent device can be realized high efficiency charge injection, high brightness, low driving voltage and high device The excellent properties such as part efficiency；Quanta point material provided by the invention also has easily controllable and diversity level structure spy simultaneously Point can sufficiently meet and cooperate the level structure of the other function layer in electroluminescent device, to realize device entirety energy level The matching of structure, to help to realize the semiconductor devices of efficient stable.

The photo luminescent devices refer to that relying on external light source is irradiated, to obtain energy, generating excitation causes to send out The device of light, ultraviolet radioactive, visible light and infra-red radiation can cause luminescence generated by light, such as phosphorescence and fluorescence.Amount of the invention Son point material can be used as the luminescent material of photo luminescent devices.

The solar battery is also referred to as photovoltaic device, and quanta point material of the invention can be used as the light absorption of solar battery Material effectively improves the properties of photovoltaic device.

The display device refers to the display panel of backlight module or the application backlight module, and the display panel can be with It applies in various products, such as display, tablet computer, mobile phone, laptop, flat panel TV, wearable display Equipment or other products comprising different size display panels.

The photodetector refers to the device that optical signal can be converted to electric signal, and principle is to be caused to be shone by radiation It penetrates material electric conductivity to change, quanta point material is applied in photodetector, have the advantage that vertical incidence light Sensitive, photoconductive response degree height, specific detecivity is high, detection wavelength is continuously adjustable and can low temperature preparation.The photoelectricity of this structure is visited Survey device in the process of running, quantum dot light photosensitive layer absorbs after photon the photo-generate electron-hole that generates to can be in built in field Effect issues estranged from this makes the structure photodetector have lower driving voltage, can be in low applying bias even 0 It can work under applying bias, and easily controllable.

The bioprobe, which refers to, modifies certain class material, makes it have the device of mark function, such as to this hair Bright quanta point material is coated, to form fluorescence probe, is applied in cell imaging or substance detection field, relatively In traditional organic fluorescent dye probe, using the bioprobe of quanta point material preparation of the invention, high with fluorescence intensity, The feature that chemical stability is good, anti-light bleaching power is strong, tool have been widely used.

The device for non-linear optical belongs to optical lasers technical field, using wide, such as opens the light for electric light And Laser Modulation, for the conversion of laser frequency, the tuning of laser frequency；Carry out optical Information Processing, improve image quality and Beam quality；As nonlinear etalon and bistable device；The highly excited level and high-resolution spectroscopy and object of research substance The transfer process and other relaxation processes etc. of matter internal energy and excitation.

Below by embodiment, the present invention is described in detail.

Embodiment 1

The preparation of the present embodiment InP quantum dot core, comprising the following steps:

0.14 mmol indium acetate, 0.6 mmol oleic acid and 20 g octadecylenes are added in 100 mL there-necked flasks, and at 150 degree Lower exhaust 30 minutes to remove the water and oxygen in reaction system；

250 degree will be warming up to after the logical full argon gas of reaction system；

0.1 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus) and the mixing of 2 mL octadecylenes are molten Liquid reacts 20 minutes under 250 degree and obtains InP quantum dot core.

Embodiment 2

The preparation of the present embodiment InPZnS quantum dot core, comprising the following steps:

0.18 mmol inidum chloride, 1 mL tetrahydrofuran, 1 mmol zinc acetate, 0.6 mL oleic acid and 9 mL octadecylenes are added to In 100 mL there-necked flasks, and 30 minutes are vented to remove the water and oxygen in reaction system under 150 degree；

280 degree will be warming up to after the logical full argon gas of reaction system；

0.06 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus), 0.4 mmol sulphur, 0.5 mL The mixed solution of tri octyl phosphine (TOP) and 0.5 mL octadecylene, and reaction obtains InPZnS quantum dot core under 280 degree.

The InPZnS quantum dot core of different emission wavelengths and luminous intensity, example can be obtained according to the difference in reaction time Such as: the emission wavelength of the InPZnS quantum dot core obtained at reaction 20 seconds is 504 nm, luminous efficiency 5%；When reacting 5 minutes The emission wavelength of the InPZnS quantum dot core of acquisition is 512 nm, luminous efficiency 25%；The InPZnS obtained when reacting 60 minutes The emission wavelength of quantum dot core is 527 nm, luminous efficiency 30%.

Embodiment 3

The preparation of the present embodiment InPZnSe quantum dot core, comprising the following steps:

0.16 mmol inidum chloride, 1 mL tetrahydrofuran, 1 mmol zinc acetate, 0.6 mL oleic acid and 9 mL octadecylenes are added to In 100 mL there-necked flasks, and 30 minutes are vented to remove the water and oxygen in reaction system under 150 degree；

300 degree will be warming up to after the logical full argon gas of reaction system；

0.12 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus), 0.02 mmol selenium, 0.5 mL The mixed solution of tri octyl phosphine (TOP) and 0.5 mL octadecylene, and reaction obtains InPZnSe quantum dot core under 300 degree.

The InPZnSe quantum dot core of different emission wavelengths and luminous intensity, example can be obtained according to the difference in reaction time Such as: the emission wavelength of the InPZnSe quantum dot core obtained at reaction 20 seconds is 503 nm, luminous efficiency 8%.

Embodiment 4

The preparation of the present embodiment InGaPZnSe quantum dot core, comprising the following steps:

0.24 mmol indium acetate, 1 mmol zinc acetate, 0.34 mmol gallium chloride, 2.8 mL oleic acid and 4 mL octadecylenes are added 30 minutes are vented into 50 mL there-necked flasks, and under 150 degree to remove the water and oxygen in reaction system；

0.19 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus), 0.01 mmol selenium, 0.2 mL The mixed solution of tri octyl phosphine (TOP) and 0.5 mL octadecylene, and reaction obtains InGaPZnSe quantum dot core under 300 degree.

The InGaPZnSe quantum dot core of different emission wavelengths and luminous intensity can be obtained according to the difference in reaction time, Such as: the emission wavelength of the InGaPZnSe quantum dot core obtained at reaction 20 seconds is 524 nm, luminous efficiency 7%.

Embodiment 5

The preparation of the present embodiment InGaPZnSeS quantum dot core, comprising the following steps:

0.24 mmol indium acetate, 1 mmol zinc acetate, 0.17 mmol gallium chloride, 2.8 mL oleic acid and 4 mL octadecylenes are added 30 minutes are vented into 50 mL there-necked flasks, and under 150 degree to remove the water and oxygen in reaction system；

0.19 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus), 0.01 mmol selenium, 0.4 The mixed solution of mmol tert-dodecylmercaotan, 0.2 mL tri octyl phosphine (TOP) and 0.5 mL octadecylene, and it is anti-under 300 degree It should obtain InGaPZnSeS quantum dot core.

The InGaPZnSeS quantum dot core of different emission wavelengths and luminous intensity can be obtained according to the difference in reaction time, Further, the high reaction activity of tert-dodecylmercaotan can inhibit the growth of core therefore can obtain compared with bob light wave significantly Long core；Such as: the emission wavelength of the InGaPZnSeS quantum dot core obtained at reaction 20 seconds is 480 nm, and luminous efficiency is 4%。

Embodiment 6

The preparation of (comparative example of no metal layer) InP/ZnSeS quantum dot, comprising the following steps:

0.16 mmol inidum chloride, 1 mL tetrahydrofuran, 0.5 mL oleic acid and 8 mL octadecylenes are added in 50 mL there-necked flasks, And 30 minutes are vented under 150 degree to remove the water and oxygen in reaction system；

0.06 mmol P (TMS) is rapidly injected into reaction system₃The mixing of (three-trimethyl silicon substrate phosphorus), 0.5 mL octadecylene Solution, and reacted 20 seconds under 280 degree and obtain InP quantum dot core；

In 30 minutes at the uniform velocity by 0.04 mmol Se-TOP predecessor, 1.2 mmol lauryl mercaptans, 2 mmol zinc oleates It is injected into reaction system；

Temperature fall obtains InP/ZnSeS quantum dot after reaction, and emission wavelength is 551 nm, and the peak width that shines is 98 Nm, luminous efficiency 5%.

Embodiment 7

The preparation of the present embodiment InP/Zn/ZnSeS quantum dot, comprising the following steps:

0.16 mmol inidum chloride, 1 mL tetrahydrofuran, 0.2 mmol zinc acetate, 1.0 mL oleic acid and 8 mL octadecylenes are added 30 minutes are vented into 50 mL there-necked flasks, and under 150 degree to remove the water and oxygen in reaction system；

0.06 mmol P (TMS) is rapidly injected into reaction system₃The mixing of (three-trimethyl silicon substrate phosphorus), 0.5 mL octadecylene Solution, and reacted 5 seconds under 280 degree and obtain InP quantum dot core；

The zinc oleate predecessor that 1.0 mmol zinc acetates and 1 mL elaidin reaction generate is rapidly injected reactant under 280 degree In system and react 30 minutes；

Temperature fall obtains InP/Zn/ZnSeS quantum dot after reaction, and emission wavelength is 526 nm, and luminous peak width is 66 nm, luminous efficiency 65%.

Embodiment 8

The preparation of the present embodiment InPZnSe/Zn/ZnSeS quantum dot, comprising the following steps:

0.24 mmol indium acetate, 1 mmol zinc acetate, 2.8 mL oleic acid and 4 mL octadecylenes are added in 50 mL there-necked flasks, And 30 minutes are vented under 150 degree to remove the water and oxygen in reaction system；

0.19 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus), 0.02 mmol selenium, 0.2 mL The mixed solution of tri octyl phosphine (TOP) and 0.5 mL octadecylene, and reacted 20 seconds under 300 degree and obtain InPZnSe quantum dot core；

1 mmol zinc oleate is injected into reaction system, and is reacted 60 minutes under 300 degree；

0.24 mmol Se-TOP predecessor and 1 mmol zinc oleate are at the uniform velocity injected into reaction system in 60 minutes；

1.2 mmol lauryl mercaptans are at the uniform velocity injected into reaction system in 15 minutes；

Temperature fall obtains InPZnSe/Zn/ZnSeS quantum dot after reaction, and emission wavelength is 607 nm, and shine peak width Degree is 85 nm, luminous efficiency 35%.

Embodiment 9

The preparation of the present embodiment InPZnS/Zn/ZnSeS quantum dot, comprising the following steps:

0.24 mmol indium acetate, 1 mmol zinc chloride, 2.8 mL oleic acid and 4 mL octadecylenes are added in 50 mL there-necked flasks, And 30 minutes are vented under 150 degree to remove the water and oxygen in reaction system；

0.19 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus), 0.4 mmol sulphur, 0.2 mL The mixed solution of tri octyl phosphine (TOP) and 0.5 mL octadecylene, and reacted 20 seconds under 280 degree and obtain InPZnS quantum dot core；

Temperature fall obtains InPZnSe/Zn/ZnSeS quantum dot after reaction, and emission wavelength is 590 nm, and shine peak width Degree is 68 nm, luminous efficiency 46%.

Embodiment 10

The preparation of the present embodiment InGaPZnSe/Zn/ZnSeS quantum dot, comprising the following steps:

By 0.24 mmol indium acetate, 0.8 mmol zinc acetate, 0.17 mmol gallium chloride, 2.8 mL oleic acid and 4 mL octadecylenes It is added in 50 mL there-necked flasks, and is vented 30 minutes under 150 degree to remove the water oxygen in reaction system；

0.19 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus), 0.02 mmol selenium, 0.2 mL The mixed solution of tri octyl phosphine (TOP) and 0.5 mL octadecylene, and reacted 20 seconds under 300 degree and obtain InGaPZnSe quantum dot Core；

Temperature fall obtains InGaPZnSe/Zn/ZnSeS quantum dot after reaction, and emission wavelength is 622 nm, glow peak Width is 69 nm, luminous efficiency 60%.

Embodiment 11

The preparation of the present embodiment InGaPZnSeS/Zn/ZnS quantum dot, comprising the following steps:

By 0.24 mmol indium acetate, 1.0 mmol zinc iodides, 0.17 mmol gallium chloride, 2.8 mL oleic acid and 4 mL octadecylenes It is added in 50 mL there-necked flasks, and is vented 30 minutes under 150 degree to remove the water oxygen in reaction system；

0.19 mmol P (TMS) is rapidly injected into reaction system₃(three-trimethyl silicon substrate phosphorus), 0.02 mmol selenium, 0.8 The mixed solution of mmol tert-dodecylmercaotan (t-DDT), 2.0 mL octylames and 0.5 mL octadecylene, and reacted under 300 degree Obtain within 20 seconds InGaPZnSeS quantum dot core；

Under 300 degree, 2 mmol zinc oleates are continuously injected into reaction system in 40 minutes；

1.2 mmol lauryl mercaptans and 1 mmol zinc oleate are at the uniform velocity injected into reaction system in 20 minutes；

Temperature fall obtains InGaPZnSeS/Zn/ZnS quantum dot after reaction, and emission wavelength is 466 nm, and shine peak width Degree is 65 nm, luminous efficiency 40%.

Embodiment 12

The preparation of the present embodiment InGaP/Ga/ZnS quantum dot, comprising the following steps:

0.24 mmol indium acetate, 0.5 mmol zinc acetate, 0.17 mmol gallium chloride, 2.8 mL oleic acid and 4 mL octadecylenes are added Enter into 50 mL there-necked flasks, and is vented 30 minutes under 150 degree to remove the water and oxygen in reaction system；

0.19 mmol P (TMS) is rapidly injected into reaction system₃The mixing of (three-trimethyl silicon substrate phosphorus), 0.5 mL octadecylene Solution, and reacted 20 seconds under 300 degree and obtain InGaP quantum dot core；

0.17 mmol gallium chloride, 1 ml octadecylene are injected into reaction system, and reacted 10 minutes under 300 degree；

1.2 mmol lauryl mercaptans, 2 mmol zinc oleates are at the uniform velocity injected into reaction system in 30 minutes；

Temperature fall obtains InGaP/Ga/ZnS quantum dot after reaction, and emission wavelength is 605 nm, and luminous peak width is 62 nm, luminous efficiency 60%.

Embodiment 13

The preparation of the present embodiment InP/Zn/ZnSe/Zn/ZnS quantum dot, comprising the following steps:

0.16 mmol inidum chloride, 1 mL tetrahydrofuran, 0.2 mmol zinc acetate, 1.0 mL oleic acid and 8 mL octadecylenes are added 30 minutes are vented into 50 mL there-necked flasks and under 150 degree to remove the water and oxygen in reaction system；

0.04 mmol Se-TOP predecessor, 0.2 mmol zinc oleate are at the uniform velocity injected into reaction system in 20 minutes；

0.5 mmol zinc oleate is disposably injected into reaction system and is reacted 30 minutes；

1.2 mmol lauryl mercaptans, 1.5 mmol zinc oleates are at the uniform velocity injected into reaction system in 30 minutes；

Temperature fall obtains InP/Zn/ZnSe/Zn/ZnS quantum dot after reaction, and emission wavelength is 521 nm, and shine peak width Degree is 63 nm, luminous efficiency 66%.

Embodiment 14

The preparation of the present embodiment InGaPZnSe/Zn/ZnSe/Zn/ZnS quantum dot, comprising the following steps:

By 0.24 mmol indium acetate, 0.8 mmol zinc acetate, 0.17 mmol gallium chloride, 2.8 mL oleic acid and 4 mL octadecylenes It is added in 50 mL there-necked flasks and is vented 30 minutes under 150 degree to remove the water oxygen in reaction system；

1.2 mmol lauryl mercaptans, 1.5 mmol zinc oleates are at the uniform velocity injected into reaction system in 15 minutes；

Temperature fall obtains InGaPZnSe/Zn/ZnSe/Zn/ZnS quantum dot after reaction, and emission wavelength is 615 nm, hair Photopeak width is 65 nm, luminous efficiency 62%.

Embodiment 15

The preparation of the present embodiment InGaP/Ga/ZnSe/Zn/ZnS quantum dot, comprising the following steps:

By 0.24 mmol indium acetate, 0.5 mmol zinc acetate, 0.17 mmol gallium chloride, 2.8 mL oleic acid and 4 mL octadecylenes It is added in 50 mL there-necked flasks and is vented 30 minutes under 150 degree to remove the water oxygen in reaction system；

0.12 mmol Se-TOP predecessor and 1 mmol zinc oleate are at the uniform velocity injected into reaction system in 30 minutes;

Temperature fall obtains InGaP/Ga/ZnSe/Zn/ZnS quantum dot after reaction, and emission wavelength is 600 nm, glow peak Width is 60 nm, luminous efficiency 60%.

In conclusion quantum dot provided by the invention includes quantum dot core and partly leading positioned at the quantum dot core outer layer Body shell layer is provided with metal layer between the quantum dot core and semiconductor shell, the metal layer is coated on outside quantum dot core, The metal layer can promote quantum to be bonded with quantum dot nuclear phase using the ligand on quantum dot core surface as connection tie Point core surface active, is conducive to further semiconductor shell growth response；Metallic atom and amount in the metal layer simultaneously Son point core is formed by crystal structure by above-mentioned bonding, can effectively be passivated quantum dot core surface, reduce its surface defect And the lattice mismatch between reduction nucleocapsid, to enhance the luminous efficiency and dimensional homogeneity of quantum dot；The semiconductor Shell is coated on outside the metal layer, and the semiconductor shell can effectively passive metal layer surface lack to reduce its surface It falls into, while the part metals atom in the metal layer can also pass through chemical bonds shape with the anion on semiconductor shell At crystal structure, the crystal structure can reduce the lattice mismatch between quantum dot nucleocapsid, further increase quanta point material Luminous efficiency and dimensional homogeneity.

It should be understood that the application of the present invention is not limited to the above for those of ordinary skills can With improvement or transformation based on the above description, all these modifications and variations all should belong to the guarantor of appended claims of the present invention Protect range.

Claims

1. a kind of quantum dot, which is characterized in that the quantum dot includes quantum dot core, coats the first metal of the quantum dot core Layer coats the first semiconductor shell of the first metal layer, coats the second metal layer of the first semiconductor shell, cladding Second semiconductor shell of the second metal layer；Wherein, in the metallic element and second metal layer in the first metal layer Metallic element independently selected from one of Zn, Hg, Al, Ga and In or a variety of.

2. quantum dot according to claim 1, which is characterized in that the material of the quantum dot core is selected from iii-v and partly leads Alloy semiconductor material composed by body material or III-V group semi-conductor material and Group II-VI semiconductor material.

3. quantum dot according to claim 2, which is characterized in that the III-V group semi-conductor material of the quantum dot core is selected From one of GaN, GaP, GaAs, InP, InAs, InAsP, GaAsP, InGaP, InGaAs and InGaAsP.

4. quantum dot according to claim 2, which is characterized in that the material of the quantum dot core is Group III-V semiconductor Alloy semiconductor material composed by material and Group II-VI semiconductor material, the III-V group semi-conductor material be selected from GaN, One of GaP, GaAs, InP, InAs, InAsP, GaAsP, InGaP, InGaAs and InGaAsP, the II-VI group semiconductor Material is in ZnSe, ZnS, ZnTe, ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, HgSeS, HgSeTe and HgSTe One kind.

5. quantum dot according to claim 1, which is characterized in that the first semiconductor shell and the second semiconductor shell Material independently selected from Group II-VI semiconductor material；

Wherein, the Group II-VI semiconductor material of the first semiconductor shell and the second semiconductor shell be selected from ZnSe, ZnS, One of ZnTe, ZnSeS, ZnSeTe, ZnSTe, HgSe, HgS, HgTe, HgSeS, HgSeTe and HgSTe.

6. quantum dot according to claim 1, which is characterized in that the quantum dot nuclear material is selected from InP or InGaP, institute The metallic element of the metallic element and second metal layer of stating the first metal layer is selected from Zn or Ga.

7. quantum dot according to claim 6, which is characterized in that the first semiconductor shell and the second semiconductor shell Material independently selected from one of ZnSe, ZnS and ZnSeS.

8. quantum dot according to claim 1, which is characterized in that the material of the quantum dot core is Group III-V semiconductor Alloy semiconductor material composed by material and Group II-VI semiconductor material, the metallic element and in the first metal layer Metallic element in two metal layers is independently selected from Zn.

9. quantum dot according to claim 8, which is characterized in that the III-V group semi-conductor material and II-VI group are partly led The alloy semiconductor material of body material be selected from InPZnS, InPZnSe, InPZnSeS, InGaPZnSe, InGaPZnS and One of InGaPZnSeS.

10. quantum dot according to claim 8, which is characterized in that the first semiconductor shell and the second semiconductor shell Layer is independently selected from one of ZnSe, ZnS and ZnSeS.

11. quantum dot according to claim 1, which is characterized in that the partial size of the quantum dot core is 2-4nm, described the The metallic element in metallic element and second metal layer in one metal layer is independently selected from Zn or Ga.

12. quantum dot according to claim 11, which is characterized in that the quantum dot is blue light quantum point.

13. quantum dot according to claim 1, which is characterized in that the partial size of the quantum dot core is 4-6nm, described the The metallic element in metallic element and second metal layer in one metal layer is independently selected from Zn or Ga.

14. quantum dot according to claim 13, which is characterized in that the quantum dot is red light quantum point or green quantum Point.

15. a kind of preparation method of quantum dot, which comprises the steps of:

The first semiconductor shell is formed on the first metal layer surface；

Second metal layer is formed in the first semiconductor shell layer surface；

The second semiconductor shell is formed on the second metal layer surface；

16. the preparation method of quantum dot according to claim 15, which is characterized in that anti-containing dispersing agent and solvent In the step of answering in system, making nonmetallic presoma and the first metal front precursor reactant forming amount sub- point core solution, the non-gold Belong to the presoma that presoma is V group element, first metal precursor is the presoma of group-III element.

17. the preparation method of quantum dot according to claim 15, which is characterized in that anti-containing dispersing agent and solvent In the step of answering in system, making nonmetallic presoma and the first metal front precursor reactant forming amount sub- point core solution, the non-gold Belong to the presoma of presoma and VI race element that presoma is V group element, first metal precursor is before group-III element Drive the presoma of body and II race element.