Light emitting device, method for manufacturing the same, and electronic device including the same
A light emitting device including a first electrode and a second electrode each having a surface opposite the other, a light emitting layer disposed between the first electrode and the second electrode, and an electronic auxiliary layer disposed between the light emitting layer and the second electrode, wherein the electron auxiliary layer includes metal oxide nanoparticles and an orthosilicate compound.
1. A light emitting device, comprising
a first electrode and a second electrode each having a surface opposite the other,
a light emitting layer disposed between the first electrode and the second electrode, and
an electronic auxiliary layer disposed between the light emitting layer and the second electrode, wherein the electron auxiliary layer comprises metal oxide nanoparticles and an orthosilicate compound.
2. The light emitting device of claim 1 , wherein at least a portion of the orthosilicate compound is bound to a surface of the metal oxide nanoparticles.
3. The light emitting device of claim 1 , wherein the metal oxide nanoparticles comprise a coating layer on a surface of the metal oxide nanoparticles, the coating layer including at least a portion of the orthosilicate compound.
4. The light emitting device of claim 1 , wherein the orthosilicate compound is represented by Chemical Formula 1:
wherein, in Chemical Formula 1,
R 11 to R 14 are independently a hydroxy group, a halogen, a substituted or unsubstituted C1 to C8 linear or branched alkoxy group, or a substituted or unsubstituted C6 to C12 aryloxy group.
5. The light emitting device of claim 1 , wherein the orthosilicate compound comprises tetramethylorthosilicate, tetraethylorthosilicate, tetrapropylorthosilicate, tetrabutylorthosilicate, or a combination thereof.
6. The light emitting device of claim 1 , wherein the orthosilicate compound is present in an amount of about 5 parts by weight to about 500 parts by weight, based on 100 parts by weight of the metal oxide nanoparticles.
7. The light emitting device of claim 1 , wherein the electron auxiliary layer further comprises a first silane compound represented by Chemical Formula 2:
(R 21 ) p —Si—(R 22 ) 4-p Chemical Formula 2
wherein, in Chemical Formula 2,
R 21 is a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C1 to C20 linear or branched alkyl group, a substituted or unsubstituted C1 to C20 aminoalkyl group, a substituted or unsubstituted C6 to C12 aryloxy group, a substituted or unsubstituted C2 to C20 alkynyl group, C2 to C20 alkenyl group, a substituted or unsubstituted C1 to C20 amine group, —C(═O)OR′, wherein R′ is a 01 to C20 linear or branched alkyl group, or —C(═O)ONR′R″, wherein R′ and R″ are independently a C1 to C20 linear or branched alkyl group,
R 22 is a hydroxy group, a halogen, a substituted or unsubstituted C1 to C8 linear or branched alkoxy group, a substituted or unsubstituted C6 to C12 aryloxy group, a substituted or unsubstituted C2 to C10 carbonylalkyl group, or a substituted or unsubstituted C2 to C10 carbonylalkoxy group, and
p is an integer of 1 to 3.
8. The light emitting device of claim 7 , wherein the first silane compound comprises trimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, triethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, pentyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, dimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dipropyldimethoxysilane, dibutyldimethoxysilane, dipentyldimethoxysilane, dihexyldimethoxysilane, dioctyldimethoxysilane, diethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, dipropyldiethoxysilane, dibutyldiethoxysilane, dipentyldiethoxysilane, dihexyldiethoxysilane, dioctyldiethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, aminomethyltrimethoxysilane, aminoethyltrimethoxysilane, aminopropyltrimethoxysilane, am inobutyltrimethoxysilane, aminopentyltrimethoxysilane, aminohexyltrimethoxysilane, aminooctyltrimethoxysilane, aminomethyltriethoxysilane, aminoethyltriethoxysilane, aminopropyltriethoxysilane, aminobutyltriethoxysilane, aminopentyltriethoxysilane, aminohexyltriethoxysilane, aminooctyltriethoxysilane, trichlorosilane, methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, butyltrichlorosilane, pentyltrichlorosilane, hexyltrichlorosilane, octyltrichlorosilane, or a combination thereof.
9. The light emitting device of claim 1 , wherein the electron auxiliary layer further comprises a second silane compound represented by Chemical Formula 3:
(R 31 ) q —Si—(R 32 ) 4-q Chemical Formula 3
wherein, in Chemical Formula 3,
R 31 is a reactive functional group capable of photo-crosslinking or thermal-crosslinking including: a vinyl group; a vinyloxy group; a (meth)acryl group; a (meth)acryloxy group; an epoxy group; a substituted or unsubstituted C2 to C30 alkenyl group; a substituted or unsubstituted C2 to C30 alkynyl group; spiro-orthoester group; a substituted or unsubstituted C3 to C30 alicyclic organic group having a double bond or a triple bond in the ring; a substituted or unsubstituted C3 to C30 heterocycloalkyl group having a double bond or a triple bond in the ring; a C3 to C30 alicyclic organic group substituted with a C2 to C30 alkenyl group or a C2 to C30 alkynyl group; or a C3 to C30 heterocycloalkyl group substituted with a C2 to C30 alkenyl group or a C2 to C30 alkynyl group,
R 32 is a hydroxy group, a halogen, a substituted or unsubstituted C1 to C8 linear or branched alkoxy group, a substituted or unsubstituted C6 to C12 aryloxy group, a substituted or unsubstituted C2 to C10 carbonylalkyl group, or a substituted or unsubstituted C2 to C10 carbonylalkoxy group, and
q is an integer of 1 to 3.
10. The light emitting device of claim 9 , wherein the second silane compound comprises vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tris(2-methoxyethoxysilane), or a combination thereof.
11. The light emitting device of claim 9 , wherein the first silane compound, and the second silane compound, are present at a concentration independent of the other though in a total amount of about 1 part by weight to about 100 parts by weight, based on 100 parts by weight of the orthosilicate compound.
12. The light emitting device of claim 1 , wherein the metal oxide nanoparticles of the electron auxiliary layer are surface-treated with a base including a hydroxy group (OH).
13. The light emitting device of claim 1 , wherein the metal oxide comprises Zn, Mg, Ca, Zr, W, Li, Ti, Y, Al, Rb, or a combination thereof.
14. The light emitting device of claim 1 , wherein the metal oxide is represented by Chemical Formula 4:
Zn 1-x M x O Chemical Formula 4
wherein, in Chemical Formula 4,
M is Mg, Ca, Zr, W, Li, Ti, Y, Al, Rb, or a combination thereof, and
0≤x≤0.5.
15. The light emitting device of claim 1 , wherein the metal oxide nanoparticles have an average particle size of about 1 nanometer to about 100 nanometer.
16. The light emitting device of claim 1 , wherein the light emitting layer comprises quantum dots.
17. The light emitting device of claim 1 , wherein the light emitting device further comprises a hole auxiliary layer including a hole injecting layer, a hole transporting layer, an electron blocking layer, or a combination thereof, between the first electrode and the light emitting layer.
18. A method of manufacturing a light emitting device, comprising
mixing metal oxide nanoparticles and an orthosilicate compound to prepare a mixed solution; and
applying the mixed solution to form an electron auxiliary layer.
19. The method of claim 18 , wherein the applying the mixed solution comprises spin coating, bar coating, spray coating, slit coating, inkjet printing, nozzle printing, spraying, or doctor blade coating.
20. The method of claim 18 , further comprising contacting the prepared electron auxiliary layer with a base including a hydroxy group.
21. The method of claim 20 , wherein the base including the hydroxy group may include alkaline metal hydroxide, alkylammonium hydroxide, or a combination thereof.
22. The method of claim 20 , wherein
the contacting of the prepared electron auxiliary layer with the base including the hydroxy group comprises
mixing the base in a solvent to prepare a base solution, and
applying the base solution on the electron auxiliary layer in the form of a coating, or dipping the electron auxiliary layer in the base solution.
23. An electronic device comprising the light emitting device of claim 1 .
24. The electronic device of claim 23 , wherein the electronic device is a display device, a sensor, a photodetector, a photoelectric conversion device, a laser, or a linear optical device.