Phase-transition optical isomer compound, transparent electroluminescent display device and method of fabricating the transparent electroluminescent display device
A phase-transition optical isomer compound is described, a transparent EL display device including the phase-transition optical isomer compound and a method of fabricating the EL display device, where a phase of the phase-transition optical isomer compound is transited by light irradiation and a second electrode of the EL display device is selectively deposited without a masking process.
1. A transparent electroluminescent display device, comprising:
a substrate comprising a sub-pixel region, the sub-pixel region including an emission area and a transparent area;
a first electrode over the substrate and in the emission area;
an emitting material layer on the first electrode;
an electron auxiliary layer on the emitting material layer and corresponding to the emission area and the transparent area; and
a second electrode on the electron auxiliary layer and corresponding to the emission area.
2. The transparent electroluminescent display device according to claim 1 , wherein the electron auxiliary layer includes a phase-transition optical isomer compound of formula:
wherein each of R1 to R4 is selected from a heteroaromatic group containing a nitrogen atom.
3. The transparent electroluminescent display device according to claim 2 , wherein the phase-transition optical isomer compound is selected from the group consisting of:
4. The transparent electroluminescent display device according to claim 2 , wherein a difference between a glass temperature in a rubbery phase of the phase-transition optical isomer compound and a glass temperature in a glassy phase of the phase-transition optical isomer compound is between about 100 to 400° C.
5. The transparent electroluminescent display device according to claim 1 , wherein the second electrode has an area smaller than an area of the electron auxiliary layer and greater than an area of the emitting material layer.
6. The transparent electroluminescent display device according to claim 1 , wherein the second electrode includes a first electrode pattern extending along a first direction and a second electrode pattern extending along the first direction and being spaced apart from the first electrode pattern along a second direction.
7. The transparent electroluminescent display device according to claim 6 , further comprising:
a connection line between adjacent sub-pixel regions,
wherein the first and second electrode patterns are electrically connected to each other by the connection line.
8. The transparent electroluminescent display device according to claim 7 , wherein the connection line is positioned between the substrate and the first electrode and extends along the second direction.
9. The transparent electroluminescent display device according to claim 7 , further comprising:
a thin film transistor between the substrate and the first electrode,
wherein the connection line is formed at the same layer and formed of the same material as a portion of the thin film transistor.
10. The transparent electroluminescent display device according to claim 6 , wherein the first electrode pattern and the second electrode pattern are connected by a bridge pattern extending from the first electrode pattern.
11. The transparent electroluminescent display device according to claim 1 , further comprising:
a cover layer covering the second electrode,
wherein the cover layer in the emission area contacts the second electrode, and the cover layer in the transparent area contacts the electron auxiliary layer.
12. A transparent electroluminescent display device, comprising:
a substrate comprising a sub-pixel region, the sub-pixel region including an emission area and a transparent area;
a first electrode over the substrate and in the emission area;
an emitting material layer on the first electrode;
an electron auxiliary layer on the emitting material layer and corresponding to the emission area and the transparent area; and
a second electrode on the electron auxiliary layer and corresponding to the emission area,
wherein the second electrode is not presented in the transparent area.
13. The transparent electroluminescent display device according to claim 12 , wherein the second electrode has an area smaller than an area of the electron auxiliary layer and greater than an area of the emitting material layer.