Method for preparing semiconductor nanocrystal siloxane composite resin composition

Abstract

The present invention relates to a method for preparing a semiconductor nanocrystal siloxane composite resin composition, and a cured product using the same. In the preparation method, the semiconductor nanocrystals are added during a non-hydrolytic sol-gel condensation reaction for forming a siloxane structure so that a siloxane resin having a dense inorganic network, which includes a siloxane bond, is encapsulated and thus is dispersed in the semiconductor nanocrystals through a chemical interaction and a chemical bond, thereby preventing a reduction in inherent characteristics (quantum efficiency) of the semiconductor nanocrystals resulting from an external oxidizing environment. Accordingly, when the curing of the resin composition is carried out, a cured product, which can be applied to various applications including a semiconductor nanocrystal siloxane composite having excellent reliability, can be provided.

Claims

1. A method for preparing a semiconductor nanocrystal siloxane composite resin composition, comprising: preparing an organosilane mixture comprising at least one organoalkoxysilane and one organosilanediol; and adding semiconductor nanocrystals during a non-hydrolytic sol-gel condensation reaction of the organosilane mixture for forming a siloxane.

2. The method for preparing a semiconductor nanocrystal siloxane composite resin composition of claim 1, wherein the semiconductor nanocrystals are added in an amount of 0.001 to 10 parts by weight based on 100 parts by weight of the siloxane resin.

3. The method for preparing a semiconductor nanocrystal siloxane composite resin composition of claim 1, wherein the organoalkoxysilane is selected from the compound represented by Chemical Formula 1 below, or a mixture thereof:
R.sup.1.sub.nSi(OR.sup.2).sub.4-n[Chemical Formula 1] (in Chemical Formula 1, each R.sup.1 is independently selected from the group consisting of a (C.sub.1C.sub.20) alkyl, (C.sub.3C.sub.8) a cycloalkyl, or a (C.sub.1C.sub.20) alkyl substituted with a (C.sub.3C.sub.8) cycloalkyl, a (C.sub.2C.sub.20) alkenyl, a (C.sub.2C.sub.20) alkynyl, and a (C.sub.6C.sub.20) aryl, each R2 is independently a linear or branched (C1C7) alkyl, and n is an integer of 0 to 3).

4. The method for preparing a semiconductor nanocrystal siloxane composite resin composition of claim 1, wherein the organoalkoxysilane is at least one selected from the group consisting of diphenylsilanediol, diisobutylsilanediol, 1,4-bis(hydroxydimethylsilyl)benzene, and 4-vinyldiphenylsilanediol.

5. The method for preparing a semiconductor nanocrystal siloxane composite resin composition of claim 1, wherein the non-hydrolytic sol-gel condensation reaction is carried out in the presence of a base catalyst.

6. The method for preparing a semiconductor nanocrystal siloxane composite resin composition of claim 5, wherein the base catalyst is at least one selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, a quaternary ammonium compound, ammonia, an amine compound, and a basic ion exchange resin.

7. The method for preparing a semiconductor nanocrystal siloxane composite resin composition of claim 1, wherein the semiconductor nanocrystals are selected from the group consisting of a Group II-VI compound, a Group II-V compound, a Group III-VI compound, a Group III-V compound, a Group IV-VI compound, a Group II-III-VI compound, a Group II-IV-VI compound, a Group II-IV-V compound, an alloy thereof, and a combination thereof.

8. The method for preparing a semiconductor nanocrystal siloxane composite resin composition of claim 1, wherein the semiconductor nanocrystal comprises a core or core-shell structure, or a multi-layered structure comprising an alloy interlayer of two or more materials.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 schematically shows the structure of the cured product using the semiconductor nanocrystal siloxane composite resin composition of the present invention.

(2) FIG. 2 shows dispersion stability of the semiconductor nanocrystals in the compositions of Example 1 and Comparative Example 1.

(3) FIG. 3 shows light-emitting uniformity of the semiconductor nanocrystals in the cured products of Example 1 and Comparative Example 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(4) Hereinafter, the effect of the present invention will be described in more detail by way of specific examples.

(5) However, these examples are given for illustrative purposes only, and the scope of the invention is not intended to be limited by these examples.

Example 1

(6) 3-(meth)acryloxypropyltrimethoxysilane and diphenylsilanediol were added to a 250 ml 2-neck flask at a molar ratio of 1:1, and then barium hydroxide monohydrate (Ba(OH).sub.2.H.sub.2O) was added as a catalyst in an amount of 0.1 mol % relative to silane.

(7) Then, the mixture was stirred at 85 C. for 5 hours to perform a non-hydrolytic condensation reaction.

(8) At this time, semiconductor nanocrystals were added as a mixture during stirring of organosilane mixture so that the semiconductor nanocrystals were dispersed during the formation of a siloxane structure, thereby preparing a siloxane composite resin composition.

(9) As for the semiconductor nanocrystals used above, Nanodot-HE-620 (trade name, Ecoflux, Korea) having a Cd-based core-shell structure was used.

(10) The semiconductor nanocrystals were dispersed in a chloroform solvent, and added in an amount of 1.0 parts by weight based on 100 parts by weight of the siloxane resin (excluding the weight of the solvent).

(11) When the non-hydrolytic sol-gel condensation reaction was completed, a photo curing catalyst (2,2-dimethoxy-2-phenylacetophenone) was added to the siloxane composite resin composition in an amount of 0.2 parts by weight based on 100 parts by weight of the entire siloxane composite resin composition, followed by stirring to prepare a semiconductor nanocrystal siloxane composite resin composition.

(12) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Example 2

(13) A semiconductor nanocrystal siloxane composite resin composition was prepared in the same manner as in Example 1, except that 3-(meth)acryloxypropyltrimethoxysilane and diisobutylsilanediol were used at a molar ratio of 1:1 instead of 3-(meth)acryloxypropyltrimethoxysilane and diphenylsilanediol and that sodium hydroxide was added as a catalyst in an amount of 0.1 mol % relative to silane.

(14) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Example 3

(15) A semiconductor nanocrystal siloxane composite resin composition was prepared in the same manner as in Example 1, except that 3-(meth)acryloxypropyltrimethoxysilane and 1,4-bis(hydroxydimethylsilyl)benzene were used at a molar ratio of 1:1 instead of 3-(meth)acryloxypropyltrimethoxysilane and diphenylsilanediol and that tetraalkylammonium hydroxide was added as a catalyst in an amount of 0.1 mol % relative to silane.

(16) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Example 4

(17) A semiconductor nanocrystal siloxane composite resin composition was prepared in the same manner as in Example 1, except that potassium hydroxide was added instead of barium hydroxide monohydrate as a catalyst in an amount of 0.1 mol % relative to silane.

(18) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Example 5

(19) A semiconductor nanocrystal siloxane composite resin composition was prepared in the same manner as in Example 1, except that aluminum hydroxide was added instead of barium hydroxide monohydrate as a catalyst in an amount of 0.1 mol % relative to silane.

(20) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Example 6

(21) A semiconductor nanocrystal siloxane composite resin composition was prepared in the same manner as in Example 1, except that 3-(meth)acryloxypropyltrimethoxysilane and 1,4-bis(hydroxydimethylsilyl)benzene were used at a molar ratio of 1:1 instead of 3-(meth)acryloxypropyltrimethoxysilane and diphenylsilanediol and that tetraalkylammonium silanolate was added as a catalyst in an amount of 0.1 mol % relative to silane.

(22) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Example 7

(23) 3-(meth)acryloxypropyltrimethoxysilane and diphenylsilanediol were added to a 250 ml 2-neck flask at a molar ratio of 1:1, and then barium hydroxide monohydrate (Ba(OH).sub.2.H.sub.2O) was added as a catalyst in an amount of 0.1 mol % relative to silane.

(24) Then, the mixture was stirred at 85 C. for 5 hours to perform a non-hydrolytic condensation reaction.

(25) semiconductor nanocrystals were added as a mixture during stirring of organosilanes so that the semiconductor nanocrystals were dispersed during the formation of a siloxane structure, thereby preparing a siloxane composite resin composition.

(26) As for the semiconductor nanocrystals used above, an In-based core-multi-shell structure (InPZnS/ZnSe/ZnS) was used.

(27) The semiconductor nanocrystals were dispersed in a chloroform solvent, and added in an amount of 1.0 part by weight based on 100 parts by weight of the siloxane resin (excluding the weight of the solvent).

(28) When the non-hydrolytic sol-gel condensation reaction was completed, a photocuring catalyst (2,2-dimethoxy-2-phenylacetophenone) was added to the siloxane composite resin composition in an amount of 0.2 parts by weight based on 100 parts by weight of the entire siloxane composite resin composition, followed by stirring to prepare a semiconductor nanocrystal siloxane composite resin composition.

(29) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Example 8

(30) A semiconductor nanocrystal siloxane composite resin composition was prepared in the same manner as in Example 7, except that 3-(meth)acryloxypropyltrimethoxysilane and diisobutylsilanediol were used at a molar ratio of 1:1 instead of 3-(meth)acryloxypropyltrimethoxysilane and diphenylsilanediol and that sodium hydroxide was added as a catalyst in an amount of 0.1 mol % relative to silane.

(31) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Comparative Examples

(32) In order to show the effect of protecting the semiconductor nanocrystals from the external oxidizing environment due to encapsulating by siloxane structure, in which semiconductor nanocrystals were added during non-hydrolytic sol-gel condensation, which is a characteristic of the siloxane composite resin composition and the cured product thereof having dispersed semiconductor nanocrystals according to the present invention, Comparative Example 1 of a hydrocarbon type not including the siloxane structure and Comparative Example 2 prepared by mixing the semiconductor nanocrystals after the formation of the siloxane structure were carried out.

Comparative Example 1

(33) As the polymer resin, a hydrocarbon-based acrylic resin (Miramer M244 (trade name), Miwon Chemical, Korea) was used.

(34) The semiconductor nanocrystals were added to the acrylic resin and then stirred at 85 C. for 5 hours to remove the solvent of solution, in which the semiconductor nanocrystals were dispersed.

(35) As the semiconductor nanocrystals used above, Nanodot-HE-620 (trade name Ecoflux, Korea) having a Cd-based core-shell structure was used.

(36) The semiconductor nanocrystals were in a state of being dispersed in a chloroform solvent, and added in an amount of 1.0 parts by weight based on 100 parts by weight of the hydrocarbon-based acrylic resin (excluding the weight of the solvent).

(37) Thereafter, 2,2-dimethoxy-2-phenylacetophenone as a photocuring catalyst was added to the resin composition in an amount of 0.2 parts by weight based on 100 parts by weight of the polymer resin, followed by stirring.

(38) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

Comparative Example 2

(39) A semiconductor nanocrystal siloxane composite resin composition was prepared in the same manner as in Example 1, except that the formation of the siloxane structure was completed and then the semiconductor nanocrystals were added.

(40) The semiconductor nanocrystal siloxane composite resin composition thus prepared was placed into a circular mold having a diameter of 1 cm and molded to a thickness of 1 mm, and then exposed to an ultraviolet lamp of a wavelength of 365 nm for 10 minutes to prepare a cured product.

[Experimental Example 1] Evaluation of Dispersion Stability and Uniformity

(41) With respect to the compositions and the cured products according to Examples 1 to 8 and Comparative Examples 1 and 2 prepared as described above, the dispersion stability and uniformity of light-emitting characteristics (emission wavelengths) of the semiconductor nanocrystals in the compositions and the cured products were confirmed using the drawings (FIGS. 2 and 3) and ARAMIS (Horiba Jobin Yvon).

(42) FIG. 2 shows dispersion stability of the semiconductor nanocrystals in the compositions of Example 1 and Comparative Example 1.

(43) FIG. 3 shows light-emitting uniformity (dispersion uniformity) of the semiconductor nanocrystals in the cured products of Example 1 and Comparative Example 1.

(44) Referring to FIG. 2, the semiconductor nanocrystals in the composition of Example 1 maintained uniform dispersion without aggregation. However, it can be confirmed that the semiconductor nanocrystals in the hydrocarbon-based acrylic resin of Comparative Example 1 were aggregated and precipitated.

(45) Referring to FIG. 3, the semiconductor nanocrystals in the cured product of Example 1 showed a uniform light-emitting wavelength in the region of 100 um.sup.2, confirming that the semiconductor nanocrystals were uniformly dispersed in the cured product without aggregation.

(46) However, it can be seen that the semiconductor nanocrystals in the cured product of Comparative Example 1 did not show a uniform light-emitting wavelength in the region of 100 um.sup.2.

(47) As a result, it was confirmed that, in the semiconductor nanocrystal siloxane composite composition and the cured product according to the present invention, the semiconductor nanocrystals were uniformly dispersed without an organic ligand exchange, thereby showing uniform light-emitting characteristics in the randomly selected region.

[Experimental Example 2] Evaluation of High Temperature Reliability (85 C.)

(48) The cured products according to Examples 1 to 8 and Comparative Examples 1 and 2 prepared as described above were exposed to an oxidizing environment of 85 C., where high heat and oxygen were present, for 40 days, and the change in the absolute quantum efficiency was measured by using an absolute quantum efficiency spectrometer manufactured by Hamamatsu (Quantaurus-QY C11347).

(49) Table 1 shows the changes in the absolute quantum efficiency after exposure to the high temperature environment in the examples and comparative examples.

(50) TABLE-US-00001 TABLE 1 Change in absolute Change in absolute quantum efficiency after quantum efficiency after exposure to 85 C. for 20 exposure to 85 C. for 40 days (%) days (%) Example 1 0 0 Example 2 0 0 Example 3 0 0 Example 4 0 2 Example 5 0.5 2 Example 6 1 1 Example 7 2 3 Example 8 2 3 Comparative 25 42 Example 1 Comparative 5 12 Example 2

(51) Referring to Table 1, it can be seen that the absolute quantum efficiency of the cured product of the semiconductor nanocrystal siloxane composite according to Examples 1 to 8 had a reduction of up to 3%, the absolute quantum efficiency of the cured product of the semiconductor nanocrystal polymer composite according to Comparative Example 1 had a reduction of 42%, and the absolute quantum efficiency of the cured product according to Comparative Example 2 had a reduction of 12%.

(52) Thus, the cured product of the siloxane composite including the semiconductor nanocrystals according to the present invention can be applied to an optical device with high reliability that maintains the quantum efficiency of the semiconductor nanocrystals in the high temperature oxidizing environment.

(53) Meanwhile, it can be seen that the absolute quantum efficiency of Comparative Example 1 not including the siloxane structure showed the greatest reduction, and the absolute quantum efficiency of Comparative Example 2 including the siloxane structure but having a difference in the preparation method (semiconductor nanocrystals were mixed after the formation of the siloxane structure) was reduced by 12%.

[Experimental Example 3] Evaluation of High Temperature and High Humidity Reliability (85 C./85% Relative Humidity)

(54) The cured products according to Examples 1 to 8 and Comparative Examples 1 and 2 prepared as described above were exposed to an oxidizing environment of 85 C./85% relative humidity where high heat, oxygen, and moisture were present, for 40 days, and the change in the absolute quantum efficiency was measured by using an absolute quantum efficiency spectrometer manufactured by Hamamatsu (Quantaurus-QY C11347).

(55) Table 2 shows the amount of change in the absolute quantum efficiency after exposure to the high temperature and high humidity environment of each of the examples and comparative examples.

(56) TABLE-US-00002 TABLE 2 Change in absolute quantum efficiency after Change in absolute exposure to 85 C./85% quantum efficiency after relative humidity for 20 exposure to 85 C. for 40 days (%) days (%) Example 1 +13.5 +13.5 Example 2 +12.5 +13 Example 3 +11 +12.8 Example 4 +10.5 +12 Example 5 +10 +11 Example 6 +12.1 +12.5 Example 7 +1 +3 Example 8 +2 +4 Comparative 19 32 Example 1 Comparative 5 8 Example 2

(57) Referring to Table 2, the absolute quantum efficiency of the cured products according to Examples 1 to 6 was increased up to 13.5% without reduction.

(58) However, it can be seen that the absolute quantum efficiency of the cured product of Comparative Example 1 was reduced by 32%, and the absolute quantum efficiency of the cured product of Comparative Example 2 was reduced by 8%.

(59) Thus, it was confirmed that the cured product of Comparative Example 1 not including the siloxane structure could not protect the semiconductor nanocrystals from the external oxidizing environment under the high temperature and high humidity.

(60) In addition, it can be seen that, since the cured product of Comparative Example 2 contained the siloxane structure but had a difference in the preparation method (semiconductor crystals were mixed after formation of the siloxane structure), the absolute quantum efficiency was reduced by 8%.

(61) Meanwhile, it can be seen that the cured product of the siloxane composite including the semiconductor nanocrystals according to the present invention showed no reduction in the quantum efficiency of the semiconductor nanocrystals in the high temperature and the high temperature and high humidity oxidizing environments as the semiconductor nanocrystals were particularly added during the non-hydrolytic sol-gel condensation reaction for forming a siloxane.

(62) Further, according to the present invention, surprisingly, it can be confirmed that the absolute quantum efficiency of the semiconductor nanocrystals remarkably increases and is maintained in a moist environment.

(63) It can be judged that water molecules present in the moist environment remove the defects on the surface of the semiconductor nanocrystals, thereby increasing the absolute quantum efficiency.

(64) Accordingly, in the present invention, the absolute quantum efficiency can be increased and maintained in the high temperature and high humidity oxidizing environment.

(65) In addition, it can be seen from Experimental Examples 1 to 3 described above that, in the composition and the cured product prepared according to the present invention, the semiconductor nanocrystals were uniformly dispersed in the cured product without an organic ligand exchange process on the surface thereof, which inevitably leads to a reduction in the quantum efficiency of semiconductor nanocrystals, thereby exhibiting uniform light-emitting characteristics.

(66) Further, the cured product of the present invention exhibited excellent stability in that the quantum efficiency, which is an important optical characteristic of the semiconductor nanocrystals, is not deteriorated, even under exposure to the high temperature and the high temperature and high humidity oxidizing environments for a long time.

(67) Therefore, the method of the present invention can achieve reliability of various applications to which the semiconductor nanocrystals are applied.