JP2017110060A - Light-emitting structure and light-emitting device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting structure using semiconductor nanoparticle phosphors, in which flocculation of the semiconductor nanoparticle phosphors between themselves, elimination of surface modification groups, or the like does not take place, and which has high light-emitting efficiency.SOLUTION: A light-emitting structure includes: a light transmitting base material having pores; a liquid dispersion medium held in the pores of the light transmitting base material; and semiconductor nanoparticle phosphors dispersed in the liquid dispersion medium, as well as a light-emitting device includes: a light source; and a wavelength conversion part having the light-emitting structures dispersed in a light transmitting medium.SELECTED DRAWING: Figure 1

Description

  The present invention comprises a translucent substrate having pores, a liquid dispersion medium retained in the pores of the translucent substrate, and a semiconductor nanoparticle phosphor dispersed in the liquid dispersion medium. The present invention relates to a light-emitting structure provided and a light-emitting device using the light-emitting structure.

  Semiconductor nanoparticle phosphors (also called quantum dots) are of commercial interest due to their size-tunable electronic properties due to quantum size effects. The variable size electronic properties can be used in a variety of applications such as biomarkers, solar power generation, catalysis, bioimaging, LEDs, general spatial illumination, and electroluminescent displays.

  For example, in Japanese Unexamined Patent Application Publication No. 2014-56896 (Patent Document 1), a base substrate, a light emitting element provided on the base substrate, and a first layer sealing portion formed on at least a part of the light emitting element ( A transparent protective layer) and a second layer sealing portion (first fluorescent layer) formed on at least a part of the first layer sealing portion, and the second layer sealing portion includes two or more types. A light emitting device having a semiconductor quantum dot (semiconductor nanoparticle phosphor) is disclosed (claims 1 and 3 of Patent Document 1). In the invention described in Patent Document 1, by interposing the first layer sealing portion (transparent protective layer) between the light emitting element and the second layer sealing portion containing the semiconductor nanoparticle phosphor, Degradation of the semiconductor nanoparticle phosphor due to the heat of the light emitting element is alleviated, and the second layer sealing portion is stabilized.

  However, in the light-emitting device described in Patent Document 1, a phosphor solution in which a semiconductor nanoparticle phosphor is dispersed in a volatile solvent is mixed with a thermosetting epoxy resin, and the first layer sealing portion is formed. The second layer sealing portion is formed by dripping and curing (paragraphs [0075] and [0078] of Patent Document 1). By redispersing the semiconductor nanoparticle phosphor dispersed in the solvent in this way in the resin, the aggregation of the semiconductor nanoparticle phosphor occurs at the time of redispersion and the light emission characteristics are deteriorated. was there.

JP 2014-56896 A

  The semiconductor nanoparticle phosphor can obtain highly efficient fluorescence characteristics when dispersed in a liquid dispersion medium. On the other hand, when mixed with a resin material as in the light emitting device disclosed in Patent Document 1, the luminous efficiency decreases. Resulting in. This is considered to be caused by changes in the surrounding environment of the semiconductor nanoparticle phosphor in the resin, such as aggregation between the semiconductor nanoparticle phosphors and elimination of surface modification groups.

  The present invention has been made in order to solve the above-mentioned problems. The object of the present invention is to achieve high luminous efficiency without causing aggregation of semiconductor nanoparticle phosphors and elimination of surface modification groups. It is to provide a novel light emitting structure using a semiconductor nanoparticle phosphor.

  The light-emitting structure of the present invention includes a translucent substrate having pores, a liquid dispersion medium held in the pores of the translucent substrate, and semiconductor nanoparticle fluorescence dispersed in the liquid dispersion medium And a body.

  In the luminescent structure of the present invention, the liquid dispersion medium is preferably held in the pores by capillary force.

In the luminescent structure of the present invention, the light-transmitting substrate preferably has a porous structure.
In the luminescent structure of the present invention, the translucent substrate is preferably in the form of a capsule.

In the luminescent structure of the present invention, the translucent substrate is preferably in the form of a capillary.
It is preferable that the light emitting structure of the present invention further includes a protective base material that covers at least the opening of the pore.

The translucent substrate in the luminescent structure of the present invention preferably has gas barrier properties.
The liquid dispersion medium in the luminescent structure of the present invention is preferably non-volatile.

The liquid dispersion medium in the light emitting structure of the present invention is preferably an ionic liquid.
The emission wavelength of the semiconductor nanoparticle phosphor in the luminescent structure of the present invention is preferably in the range of 380 to 750 nm.

The light emitting structure of the present invention preferably includes a plurality of light emission peaks.
The present invention also provides a light-emitting device including a light source and a wavelength conversion unit in which the above-described light-emitting structure of the present invention is dispersed in a light-transmitting medium.

  In the light emitting device of the present invention, the light source may have a frame body mounted in the recess, and the wavelength conversion unit may be filled with the light source and the recess with the light source.

  In the light emitting device of the present invention, the light source may have a frame body mounted in the recess, and the wavelength conversion unit may be a film-like object that covers at least a part of the opening of the recess.

  According to the present invention, since the liquid dispersion medium in which the semiconductor nanoparticle phosphor is dispersed is held in the pores of the translucent substrate without using the resin curing process, Changes in the surrounding environment of the semiconductor nanoparticle phosphor, such as aggregation and removal of surface modifying groups, are unlikely to occur, and the light emission characteristics of the semiconductor nanoparticle phosphor remain dispersed in a liquid dispersion medium so that the semiconductor nanoparticle phosphor can function stably. It is possible to provide a light-emitting structure that hardly deteriorates. The present invention also provides a light-emitting device using such a light-emitting structure.

It is a figure which shows typically the luminescent structure 1 of the 1st embodiment of this invention. It is a graph which compares the luminous efficiency of the light emitting structure of the structure shown in FIG. 1, and the case where the same semiconductor nanoparticle fluorescent substance is dispersed in the same liquid dispersion medium and then mixed with a silicone resin. It is a figure which shows typically the luminescent structure 11 of the 2nd embodiment of this invention. It is a figure which shows typically the luminescent structure 21 of the 3rd embodiment of this invention. It is a figure which shows typically the luminescent structure 31 of the 4th embodiment of this invention. It is a figure which shows typically the luminescent structure 41 of the 5th embodiment of this invention. FIG. 7A is a view schematically showing a light emitting structure according to a sixth embodiment of the present invention, and FIG. 7A shows a light emitting structure which is a modification of the light emitting structure 21 of the example shown in FIG. FIG. 7B shows a light emitting structure 31 ′ which is a modification of the light emitting structure 31 of the example shown in FIG. 5, and FIG. 7C shows the example shown in FIG. A light emitting structure 41 ′, which is a modification of the light emitting structure 41, is shown. It is a figure which shows typically the luminescent structure 51 of the 7th embodiment of this invention. It is a figure which shows typically the luminescent structure 61 of the 8th embodiment of this invention. It is a figure which shows typically the luminescent structure 71 of the 9th embodiment of this invention. It is a figure which shows typically the luminescent structure 81 of the 10th embodiment of this invention. It is a figure which shows typically the luminescent structure 91,101,102 of the 11th embodiment of this invention. It is a figure which shows typically the light-emitting device 111 of the 12th embodiment of this invention. It is a figure which shows typically the light-emitting device 111 of the 13th embodiment of this invention.

<Luminescent structure>
(Luminescent structure of the first embodiment)
FIG. 1 is a diagram schematically showing a luminescent structure 1 according to a first embodiment of the present invention. As shown in the example shown in FIG. 1, the light-emitting structure 1 of the present invention includes a translucent substrate 3 having pores 4 and a liquid dispersion held in the pores 4 of the translucent substrate 3. A medium 5 and a semiconductor nanoparticle phosphor 2 dispersed in the liquid dispersion medium 5.

  According to the light emitting structure of the present invention, since the liquid dispersion medium in which the semiconductor nanoparticle phosphor is dispersed is held in the pores of the translucent substrate without using the resin curing process, It was dispersed in a liquid dispersion medium so that the surrounding environment of the semiconductor nanoparticle phosphor did not easily change, such as aggregation between particle phosphors and elimination of surface modification groups, and the semiconductor nanoparticle phosphor could function stably. As a result, the light emission characteristics are hardly deteriorated. In addition, since the translucent substrate 3 surrounds the semiconductor nanoparticle phosphor 2 in a state dispersed in the liquid dispersion medium, the semiconductor nanoparticle phosphor 2 is not easily exposed to air, moisture, and the like. In addition, the long-term stability of the semiconductor nanoparticle phosphor is improved.

  Here, FIG. 2 shows a light-emitting structure having the structure shown in FIG. 1 (core-shell CdSe / ZnS having an emission wavelength of 620 nm as a semiconductor nanoparticle phosphor, and N, N, N-trimethyl-N-propyl as a liquid dispersion medium. Ammonium bis (trifluoromethanesulfonyl) imide, Daiso Gel (manufactured by Daiso Chemical Co., Ltd.) as the translucent substrate) and the same semiconductor nanoparticle phosphor in the same liquid dispersion medium, It is a graph which compares and shows the luminous efficiency (measured by C9920-02G (made by Hamamatsu Photonics)) with the case where it mixes with OE-7620 (made by Dow Corning), and a vertical axis | shaft is luminous efficiency. In the graph of FIG. 2, A shows the light emitting structure of the present invention, and B shows the case where it is mixed with a silicone resin. As is clear from FIG. 2, when the efficiency of the semiconductor nanoparticle phosphor when dispersed in the liquid dispersion medium is used as a reference, B decreased to about 0.3, whereas A remained at about 0.7. . Thus, it can be seen that the light emitting structure of the present invention is less likely to deteriorate the light emitting characteristics of the semiconductor nanoparticle phosphor as compared with the case of mixing with a resin.

  The light-emitting structure of the present invention is configured to “hold” the liquid dispersion medium in which the semiconductor nanoparticle phosphor is dispersed in the pores of the translucent substrate. For example, in the hollow outer shell This is different from the configuration in which the liquid in which the semiconductor nanoparticle phosphor is dispersed is “encapsulated”. In order to “enclose” within the hollow outer shell, the liquid for dispersing the semiconductor nanoparticle phosphor is limited, but the liquid dispersion medium in which the semiconductor nanoparticle phosphor is dispersed is used as a light-transmitting substrate. In the present invention, which is configured to “hold” in the pores, the liquid dispersion medium to be used is not particularly limited.

  The semiconductor nanoparticle phosphor 2 according to the present invention has high luminous efficiency, has a very narrow emission line width, and has the characteristics that the emission wavelength can be controlled by adjusting the nanoparticle size. In general, when the dispersibility is good in a liquid dispersion medium, the light emission efficiency is high, but when dispersed in a solid such as a resin, energy deactivation occurs between the nanoparticle phosphors due to aggregation and the efficiency is lowered. Further, the use of the semiconductor nanoparticle phosphor has an advantage that the emission wavelength can be precisely controlled by the composition control.

  The raw material of the semiconductor nanoparticle phosphor is not particularly limited, and CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InN, InP, InAs, InSb, AlP, conventionally used as the semiconductor nanoparticle phosphor. It may be at least one selected from AlS, AlAs, AlSb, GaN, GaP, GaAs, GaSb, PbS, PbSe, Si, Ge, MgS, MgSe, and MgTe. In addition, semiconductor nanoparticle phosphors are known to those skilled in the art two-component core, three-component core, four-component core, core-shell or core multi-shell, doped semiconductor nanoparticle phosphor or tilted It may be a semiconductor nanoparticle phosphor.

  The shape of the semiconductor nanoparticle phosphor is not particularly limited, but a semiconductor nanoparticle phosphor having a conventionally known appropriate shape such as a spherical shape, a rod shape, or a wire shape can be used without any particular limitation. In particular, from the viewpoint of easy control of light emission characteristics by shape control, it is preferable to use a spherical semiconductor nanoparticle phosphor.

  The particle diameter of the semiconductor nanoparticle phosphor can be appropriately selected according to the raw material and the desired emission wavelength, and is not particularly limited, but is preferably in the range of 1 to 20 nm, and in the range of 2 to 5 nm. More preferably. This is because when the particle diameter of the semiconductor nanoparticle phosphor is less than 1 nm, the ratio of the surface area to the volume increases, so that surface defects tend to be dominant and the effect tends to decrease. This is because when the particle diameter of the body exceeds 20 nm, the dispersed state tends to decrease and aggregation / sedimentation tends to occur. Here, when the shape of the semiconductor nanoparticle phosphor is spherical, the particle diameter refers to, for example, an average particle diameter measured by a particle size distribution measuring apparatus or a particle size observed by an electron microscope. When the semiconductor nanoparticle phosphor is rod-shaped, the particle diameter refers to the size of the short axis and the long axis measured by, for example, an electron microscope. Furthermore, when the shape of the semiconductor nanoparticle phosphor is a wire shape, the particle diameter refers to the size of the short axis and the long axis measured by, for example, an electron microscope.

  In the luminescent structure of the present invention, the semiconductor nanoparticle phosphor is preferably dispersed in the range of 0.00001 to 100 parts by weight with respect to 100 parts by weight of the liquid dispersion medium, and 0.001 to 50 parts by weight. More preferably, it is dispersed within the range of parts. This is because when the semiconductor nanoparticle phosphor is less than 0.00001 part by weight with respect to 100 parts by weight of the liquid dispersion medium, the concentration tends to be low and sufficient light emission intensity cannot be obtained. This is because when the amount exceeds 100 parts by weight with respect to parts by weight, the dispersibility is poor and the semiconductor nanoparticle phosphors tend to aggregate with each other, and the light emission efficiency decreases.

  In the luminescent structure of the present invention, the liquid dispersion medium is not particularly limited, but from the viewpoint of stably dispersing the semiconductor nanoparticle phosphor and obtaining good luminous efficiency, toluene, chloroform, hexane, ethanol, An organic dispersion medium such as methanol or an aqueous dispersion medium is preferred. Among them, it is preferable to use toluene or chloroform as the liquid dispersion medium because the organic dispersion medium having polarity can stably disperse the surface-modified semiconductor nanoparticle phosphor.

The translucent substrate 3 in the light emitting structure of the present invention has translucency and has pores 4. As a material for forming such a translucent base material 3, for example, at least one of main components is silicone resin, epoxy resin, SiO ₂ , Al ₂ O ₃ , ZnO, In ₂ O ₃ , SnO ₂ , Examples thereof include TiO ₂ . FIG. 1 shows an example in which the pores 4 of the translucent substrate 3 are formed so that at least some of them communicate with each other. Of course, a commercially available product may be used as such a translucent substrate 3, and for example, Daiso Gel (manufactured by Daiso Chemical Co., Ltd.) may be mentioned as a suitable example. The outer shape of the translucent substrate 3 is not particularly limited, and examples thereof include a spherical shape (true spherical shape, elliptic spherical shape), a rod shape, a prismatic shape, and a film shape.

  In the luminescent structure 1 of the present invention, the liquid dispersion medium can be injected and held from the pores 4 into the translucent substrate 3, so that the liquid dispersion medium is not limited. Due to the translucency of the material, it is possible to achieve both high luminous efficiency and handleability as a solid (powder) without lowering the luminous efficiency when taking in and taking out excitation light and fluorescence.

(Luminescent Structure of Second Embodiment)
FIG. 3 is a diagram schematically showing the luminescent structure 11 according to the second embodiment of the present invention. The example luminescent structure 11 shown in FIG. 3 has the same configuration as that of the example luminescent structure 1 shown in FIG. 1 except for a part thereof, and the same parts are the same. The description is abbreviate | omitted and attached | subjected.

  In the example luminescent structure 11 shown in FIG. 3, the liquid dispersion medium is held in the pores by capillary force. Thus, in the luminescent structure of the present invention, it is preferable that the liquid dispersion medium is held in the pores by capillary force. Thereby, liquid leakage of the liquid dispersion medium from the light emitting structure is prevented, and the handleability is improved.

  Here, in general, the structure having pores has a function of adsorbing and holding the liquid dispersion medium by capillary action. When the following relational expression is satisfied, the liquid inside can be held by capillary action.

M × g <2πr ² × T
M: Mass of liquid dispersion medium [kg]
g: Gravity acceleration [m / s ² ]
r: radius of pore [m]
T: surface tension of liquid / side surface [N / m]
When the above relationship is established between the type and retention amount of the liquid dispersion medium and the pore diameter of the structure, capillary action appears, preventing liquid leakage from the pores, making it easy to handle the luminescent structure as powder Become.

(Luminescent Structure of Third Embodiment)
FIG. 4 is a diagram schematically showing a luminescent structure 21 according to a third embodiment of the present invention. The example luminescent structure 21 shown in FIG. 4 has the same configuration as the luminescent structure 1 shown in FIG. 1 except for a part thereof, and the same configuration is applied to parts having the same configuration. The description is abbreviate | omitted and attached | subjected. The translucent substrate 22 in the light emitting structure 21 of the example shown in FIG. 4 has a porous structure. Here, the porous structure is a structure characterized by including many pores inside the translucent substrate 22.

  Since the translucent substrate 22 has a porous structure, it includes a large number of pores, so that there is an advantage that a large amount of liquid dispersion medium can be held in the pores. Furthermore, by dispersing the phosphor nanoparticle phosphor in a liquid dispersion medium and holding it on a light-transmitting substrate having a porous structure, it becomes possible to handle the obtained luminescent structure as a solid fluorescent member, The light emitting structure can be easily redispersed in the resin.

  In order to obtain the translucent substrate 22 having a porous structure, for example, a sol-gel precursor (metal alkoxide, etc.) and a surfactant are mixed in water as a material for forming the translucent substrate, and water decomposition or condensation is performed. By forming a silica network and removing the organic template by heat treatment, a translucent substrate having a porous structure mainly composed of silica with pores is obtained. Alternatively, as a matter of course, a commercially available product may be used as the translucent substrate 3 having a porous structure, for example, Daiso Gel (manufactured by Daiso Chemical Co., Ltd.), M.I. S. A suitable example is GEL (manufactured by AGC S-Tech Co., Ltd.).

(Luminescent Structure of Fourth Embodiment)
FIG. 5 is a diagram schematically showing a luminescent structure 31 according to a fourth embodiment of the present invention. The light emitting structure 31 of the example shown in FIG. 5 has the same configuration as the light emitting structure 1 of the example shown in FIG. 1 except for a part, and the same parts are the same. The description is abbreviate | omitted and attached | subjected.

  The light-emitting structure 31 of the present invention may use a capsule-like translucent substrate 32 as in the example shown in FIG. In this case, the translucent substrate 32 has pores 33 communicating with the internal space, and the liquid in which the semiconductor nanoparticle phosphor 2 is injected into the internal space through the pores 33 is dispersed. A dispersion medium 5 is accommodated. By using such a capsule-like translucent base material 32, the pore volume per volume is large compared to the embodiment shown in FIG. 1, and the amount of the liquid dispersion medium retained in the semiconductor nanoparticle phosphor There is an advantage that it is easy to increase.

  As such a capsule-shaped translucent base material 32, what was formed, for example with materials, such as a silica, can be used suitably. Of course, a commercial product may be used as such a capsule-like translucent substrate 32.

(Luminescent Structure of Fifth Embodiment)
FIG. 6 is a diagram schematically showing a luminescent structure 41 according to a fifth embodiment of the present invention. The light emitting structure 41 in the example shown in FIG. 6 has the same configuration as the light emitting structure 1 in the example shown in FIG. 1 except for a part thereof, and the parts having the same configuration are the same. The description is abbreviate | omitted and attached | subjected.

  As shown in the example shown in FIG. 6, the light emitting structure 41 of the present invention includes a translucent base material 43 having a capillary shape (cylindrical structure having pores), and an internal space (pore) 44. In addition, the liquid dispersion medium 3 in which the semiconductor nanoparticle phosphor 2 is dispersed may be accommodated. By using the capillary-like translucent substrate 43 in this way, an arrayed excitation light source and capillaries are arranged side by side as compared with the embodiment shown in FIG. There is an advantage that can be used.

  As such a capillary-like translucent base material 43, for example, a material formed of a material such as silica can be suitably used. Of course, a commercial product may be used as such a capillary-like translucent substrate 43, and for example, a DURAN capillary (manufactured by Shot Japan Co., Ltd.) may be mentioned as a suitable example.

(Luminescent Structure of Sixth Embodiment)
FIG. 7 is a diagram schematically showing a light emitting structure according to a sixth embodiment of the present invention. FIG. 7A shows a modification of the light emitting structure 21 of the example shown in FIG. A light emitting structure 21 ′, FIG. 7B shows a light emitting structure 31 ′ which is a modification of the light emitting structure 31 of the example shown in FIG. 5, and FIG. A light emitting structure 41 ′, which is a modification of the light emitting structure 41 of the example shown in FIG. Note that the light emitting structures 21 ′, 31 ′, and 41 ′ shown in FIGS. 7A, 7B, and 7C have protective substrates 24, 34, and 45 that cover at least the openings of the pores, respectively. The components have the same configuration except that they are further provided, and portions having the same configuration are denoted by the same reference numerals and description thereof is omitted.

  As described above, after the liquid dispersion medium 5 in which the semiconductor nanoparticle phosphor 2 is dispersed is held in the translucent base material having the pores 23, 33, 44, at least the pores 23, 33, 44. Covering with protective substrates 24, 34, and 45 so as to block the gas prevents the gas from entering the pores and improves the long-term stabilization of the luminous efficiency of the semiconductor nanoparticle phosphor. . Moreover, by providing the protective base materials 23, 34, and 45, liquid leakage of the liquid dispersion medium from the light emitting structure can be physically prevented, and handling properties are improved.

  Furthermore, when the liquid dispersion medium in which the semiconductor nanoparticle phosphor is dispersed is directly covered with the protective base material to be included in the protective base material, the liquid dispersion medium to be included is limited. For example, the core cell There are also limited methods of inclusion, such as the basation method. On the other hand, in the case of the light emitting structure of the example shown in FIG. 7, the pore opening is maintained in a state in which the liquid dispersion medium in which the semiconductor nanoparticle phosphor is dispersed is held in the translucent substrate having pores. Since the protective base material is provided so as to cover at least the protective base material, for example, the protective base material can be easily provided in the manner of forming a film on the solid. There are no particular restrictions.

  The protective substrate only needs to be provided so as to block at least the pores, and covers the entire outermost shell of the luminescent structure as in the example shown in FIGS. 7 (a) and 7 (b). Or may be provided so as to block only the pores as in the example shown in FIG.

The material for forming the protective substrate is not particularly limited. For example, as at least one of the main components, silicone resin, epoxy resin, SiO ₂ , Al ₂ O ₃ , ZnO, In ₂ O ₃ , SnO ₂ , TiO _{2 and the} like can be used. Can be mentioned. Especially, it is preferable to use the protective base material formed with the silicone resin from the favorable workability and high stability. Of course, a commercially available product may be used as such a protective base material. For example, KER-2500 (manufactured by Shin-Etsu Chemical Co., Ltd.) may be mentioned as a suitable example.

(Luminescent Structure of Seventh Embodiment)
FIG. 8 is a diagram schematically showing a luminescent structure 51 according to a seventh embodiment of the present invention. The light emitting structure 51 in the example shown in FIG. 8 has the same configuration as the light emitting structure 1 in the example shown in FIG. 1 except for a part, and the same parts are the same. The description is abbreviate | omitted and attached | subjected.

In the light emitting structure 51 of the example shown in FIG. 8, the translucent substrate 52 has gas barrier properties. Here, the “gas barrier property” means that the oxygen permeability measured by a method such as a coulometric method or a gas chromatographic method is 10,000 cc / m ² / day or less (more preferably, 0 to 300 cc / m ² / day). (Within range). By using the translucent substrate 52 having such a gas barrier property, it is difficult for gas to enter the pores except for the openings of the pores 53, so that the semiconductor nanoparticle phosphor is deteriorated by the gas. There is an advantage that the emission efficiency of the semiconductor nanoparticle phosphor can be stabilized for a long period of time.

As a material for forming such a light-transmitting substrate 52 having gas barrier properties, for example, at least one of the main components is silicone resin, epoxy resin, SiO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SnO _2. , TiO ₂ , ZnO and the like. Among them, it is preferable to have low oxygen permeability, and it is preferable to use a translucent substrate formed of a modified silicone resin as a translucent substrate having gas barrier properties. Of course, commercially available products may be used as such a light-transmitting base material having gas barrier properties. For example, OE-7620 (manufactured by Dow Corning), SS-6503 (manufactured by Sanyu Rec Co., Ltd.) and the like are suitable examples. Can be mentioned.

(Luminescent Structure of Eighth Embodiment)
FIG. 9 is a diagram schematically showing a luminescent structure 61 according to an eighth embodiment of the present invention. The light emitting structure 61 in the example shown in FIG. 9 has the same configuration as the light emitting structure 1 in the example shown in FIG. 1 except for a part thereof, and the parts having the same configuration are the same. The description is abbreviate | omitted and attached | subjected.

  In the light emitting structure 61 of the example shown in FIG. 9, a non-volatile liquid dispersion medium is used as the liquid dispersion medium 62 in which the semiconductor nanoparticle phosphor is dispersed. Here, “nonvolatile” refers to a liquid having a high boiling point (preferably 100 ° C. or higher). Preferable examples of such a non-volatile liquid dispersion medium include isobutyl alcohol, toluene, xylene, ethylene glycol monoethyl ether and the like.

  In the present invention, a non-volatile liquid dispersion medium may be used like the light emitting structure of the eighth embodiment. By using such a non-volatile liquid dispersion medium, the liquid dispersion medium is less likely to vaporize while being held in the pores of the light emitting structure, and it is easy to maintain the state held in the pores. In addition, there is an advantage that deterioration of the semiconductor nanoparticle phosphor due to evaporation of the liquid dispersion medium can be prevented.

(Luminescent structure of ninth embodiment)
FIG. 10 is a diagram schematically showing a luminescent structure 71 according to a ninth embodiment of the present invention. The light emitting structure 71 in the example shown in FIG. 10 has the same configuration as the light emitting structure 1 in the example shown in FIG. 1 except for a part thereof, and the same parts are the same. The description is abbreviate | omitted and attached | subjected.

  In the example luminescent structure 71 shown in FIG. 10, an ionic liquid is used as the liquid dispersion medium 72 in which the semiconductor nanoparticle phosphor is dispersed. The ionic liquid has a characteristic that it does not have a vapor pressure and hardly evaporates, and the ionic liquid can be held in a more retained state than the non-volatile liquid dispersion medium. In addition, the ionic liquid has an effect of electrostatically stabilizing the surface of the semiconductor nanoparticle phosphor to stably disperse it without agglomeration, and a luminescent structure exhibiting high luminous efficiency and luminance can be obtained.

  Examples of the ionic liquid include 2- (methacryloyloxy) -ethyltrimethylammonium bis (trifluoromethanesulfonyl) imide, 1- (3-acryloyloxy-propyl) -3-methylimidazolium ethyltrimethylammonium bis (trifluoromethanesulfonyl). Imido, N, N, N-trimethyl-N-propylammonium bis (trifluoromethanesulfonyl) imide, N, N-dimethyl-N-methyl-2- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide, 1 -Allyl-3-butylimidazolium tetrafluoroborate, 1-methyl-3-octylimidazolium hexafluorophosphate and the like. Among these, since ionic liquids containing impurities such as water tend to lower the long-term stability of the semiconductor nanoparticle phosphor, N, N, N-trimethyl is hydrophobic as an ionic liquid and can easily separate water. It is preferable to use -N-propylammonium bis (trifluoromethanesulfonyl) imide.

(Luminescent Structure of Tenth Embodiment)
FIG. 11 is a diagram schematically showing a luminescent structure 81 according to a tenth embodiment of the present invention. The light emitting structure 81 in the example shown in FIG. 11 has the same configuration as the light emitting structure 1 in the example shown in FIG. 1 except for a part, and the same parts are the same. The description is abbreviate | omitted and attached | subjected.

  In the example shown in FIG. 11, a semiconductor nanoparticle phosphor 82 having an emission wavelength in the range of 380 to 750 nm (that is, having a band gap that emits visible light) is used. By using a semiconductor nanoparticle phosphor having such an emission wavelength, there is an advantage that a light source of an arbitrary color can be obtained by a combination with an excitation light source such as a blue LED. When a semiconductor nanoparticle phosphor having an emission wavelength of less than 380 nm or an emission wavelength of more than 750 nm is used, it appears to be almost black because it is outside the visible light region, so it is not suitable as a phosphor for obtaining a light source of any color. .

Examples of the semiconductor nanoparticle phosphor 82 having the above-described emission wavelength include InP, InN, InAs, InSb, InBi, ZnO, In ₂ O ₃ , Ga ₂ O ₃ , ZrO ₂ , In ₂ S ₃ , and Ga ₂ S. ₃ , at least one selected from In ₂ Se ₃ , Ga ₂ Se ₃ , In ₂ Te ₃ , Ga ₂ Te ₃ , CdSe, CdTe, CdS, and the like. In addition, the semiconductor nanoparticle phosphor 82 may be a semiconductor nanoparticle phosphor having a conventionally known appropriate shape such as a spherical shape, a rod shape, or a wire shape, as described above.

(Luminescent structure of eleventh embodiment)
FIG. 12 is a diagram schematically showing the luminescent structures 91, 101, 102 according to the eleventh embodiment of the present invention. Note that the luminescent structures 91, 101, and 102 in the example shown in FIG. 11 have the same configuration except for a part of the luminescent structure 1 in the example shown in FIG. 1, and have the same configuration. Parts are denoted by the same reference numerals and description thereof is omitted.

  By realizing the luminescent structure so as to have a plurality of emission peaks, there is an advantage that adjustment to a target emission spectrum is easy. For example, by using a light emitting structure having a red light emission peak and a green light emission peak, white light with good color rendering can be easily realized when combined with a blue excitation light source. As a method of realizing a light emitting structure having a plurality of light emission peaks, for example, two types of semiconductor nano-particles having light emission peaks different from each other, such as the light emitting structure 91 in the example shown in FIG. Particle phosphors (for example, semiconductor nanoparticle phosphors emitting red light and semiconductor nanoparticle phosphors emitting green light) 92 and 93 may be dispersed in a liquid dispersion medium. Further, as in the example shown in FIG. 12B, semiconductor nanoparticle phosphors having different emission peaks (for example, a semiconductor nanoparticle phosphor emitting red light and a semiconductor nanoparticle phosphor emitting green light) 92, By using two types of light emitting structures 101 and 102 in which a liquid dispersion medium in which 93 is dispersed is held in another translucent substrate 3, a light emitting structure having a plurality of light emission peaks is realized. You may make it do.

<Light emitting device>
(Light-emitting device of 12th embodiment)
Here, FIG. 13 is a diagram schematically showing a light emitting device 111 according to a twelfth embodiment of the present invention. The present invention includes a light source (LED) and a wavelength conversion unit 112 in which the light emitting structure according to any of the first to eleventh embodiments described above is dispersed in a light transmitting medium 115 (LED). Package) 111 is also provided. The light-emitting structure of the present invention has good handleability (handling property), and is manufactured in the same form as a phosphor currently used commercially by making it to the same size as a phosphor currently used. Can be used without changing the current process. In the light-emitting device shown in FIG. 13, any conventionally known appropriate light source 113, translucent medium 115, frame 114, lead wire, and the like other than the light-emitting structure can be used without any particular limitation. The light emitting device 111 of the example of the present invention shown in FIG. 13 has a frame 114 in which a light source 113 is mounted in a recess, and the wavelength conversion unit is filled with the light source and the recess with the light source.

  In the light emitting device of the present invention, the light source is not particularly limited, and a light emitting diode (LED), a laser diode (LD), or the like can be used.

  In the light-emitting device 41 of the present invention, the light-transmitting medium for encapsulating the light source 113 and the light-emitting structure is not particularly limited, and epoxy, silicone and (meth) acrylate, silica glass, silica gel, siloxane, Sol gel, hydrogel, agarose, cellulose, epoxy, polyether, polyethylene, polyvinyl, polydiacetylene, polyphenylene vinylene, polystyrene, polypyrrole, polyimide, polyimidazole, polysulfone, polythiophene, polyphosphate, poly (meth) acrylate, polyacrylamide, polypeptide And polysaccharides. A plurality of these may be used as a light-transmitting medium.

(Light-emitting device of thirteenth embodiment)
Here, FIG. 14 is a diagram schematically showing a light emitting device 121 according to a thirteenth embodiment of the present invention. The light emitting device 121 of the example shown in FIG. 14 has a frame 114 in which a light source 113 is mounted in a recess, and the wavelength converter 112 is a film-like object 122 that covers at least a part of the opening of the recess. By using such a film-like material 122 as the wavelength conversion unit 112, the excitation light source and the wavelength conversion unit, as shown in FIG. The arrangement incorporating the space in the recesses has the advantage that the effect of heat from the excitation light source is mitigated, and the long-term stability of the semiconductor nanoparticle phosphor contained in the wavelength conversion unit can be improved. The film-like material used as the wavelength conversion part can be produced by a conventionally known appropriate material and method, and the forming material and the production method are not particularly limited.

  DESCRIPTION OF SYMBOLS 1 Luminescent structure, 2 Semiconductor nanoparticle fluorescent substance, 3 Translucent base material, 4 pore, 5 Liquid dispersion medium, 11 Luminescent structure, 12 Translucent base material, 13 Porous, 21 Luminous structure Body, 22 translucent substrate, 23 pores, 31 luminescent structure, 32 capsule-shaped translucent substrate, 33 pores, 41 luminescent structure, 43 capillary-shaped translucent substrate, 44 Pore part, 21 'luminescent structure, 24 protective substrate, 31' luminescent structure, 34 protective substrate, 41 'luminescent structure, 45 protective substrate, 51 luminescent structure, 52 translucent Substrate, 53 pores, 61 luminescent structure, 62 liquid dispersion medium, 71 luminescent structure, 72 liquid dispersion medium, 81 luminescent structure, 82 semiconductor nanoparticle phosphor, 91 luminescent structure, 92 semiconductor Nanoparticle phosphor, 93 Semiconductor nanoparticle phosphor, 101 Light emission Structure 102 emitting structure 111 light emitting devices, 112 wavelength converting unit, 113 light source, 114 frame, 115 medium, 121 light-emitting device, 122 film material.

Claims (14)

A translucent substrate having pores;
A liquid dispersion medium held in the pores of the translucent substrate;
A luminescent structure comprising a semiconductor nanoparticle phosphor dispersed in the liquid dispersion medium.   The luminescent structure according to claim 1, wherein the liquid dispersion medium is held in the pores by a capillary force.   The luminescent structure according to claim 1, wherein the translucent substrate has a porous structure.   The luminescent structure according to claim 1, wherein the translucent substrate is in a capsule shape.   The luminescent structure according to claim 1 or 2, wherein the translucent substrate has a capillary shape.   The luminescent structure according to any one of claims 1 to 5, further comprising a protective base material covering at least the opening of the pore.   The luminescent structure according to any one of claims 1 to 6, wherein the translucent substrate has gas barrier properties.   The luminescent structure according to claim 1, wherein the liquid dispersion medium is nonvolatile.   The luminescent structure according to any one of claims 1 to 7, wherein the liquid dispersion medium is an ionic liquid.   The luminescent structure according to any one of claims 1 to 9, wherein an emission wavelength of the semiconductor nanoparticle phosphor is in a range of 380 to 750 nm.   The luminescent structure according to any one of claims 1 to 10, comprising a plurality of luminescence peaks.   A light-emitting device provided with a light source and the wavelength conversion part by which the luminescent structure of any one of Claims 1-11 was disperse | distributed in the medium which has translucency.   The light-emitting device according to claim 12, wherein the light source has a frame body mounted in the concave portion, and the wavelength conversion unit has the concave portion filled with the medium together with the light source.   The light-emitting device according to claim 12, wherein the light source has a frame body mounted in the recess, and the wavelength conversion unit is a film-like object that covers at least a part of the opening of the recess.

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