Organic light emitting display (OLED) and its method of fabrication

1. An Organic Light Emitting Display (OLED), comprising:

a transparent substrate;

a photochromatic layer arranged on a first surface of the transparent substrate;

at least one transparent Thin Film Transistor (TFT) arranged on a second surface of the transparent substrate; and

an organic light emitting device arranged on and electrically connected to the transparent TFT,

wherein said first surface of the transparent substrate and said second surface of the transparent substrate are on opposite sides of said transparent substrate.

2. The OLED as claimed in claim 1 , wherein the photochromatic layer comprises at least one of an inorganic material an organic material, and a glass material that visibly changes in response to light.

3. The OLED as claimed in claim 2 , wherein the photochromatic layer comprises a borosilicate containing either Ag or halogen compound crystals.

4. The OLED as claimed in claim 1 , wherein the color of the photochromatic layer changes in response to being exposed to either light or UV rays.

5. The OLED as claimed in claim 1 , wherein the transparent TFT comprises a semiconductor layer, a gate electrode, and source and drain electrodes.

6. The OLED as claimed in claim 5 , wherein the semiconductor layer comprises a material having a wide band gap of at least 3.0 eV.

7. The OLED as claimed in claim 5 , wherein the semiconductor layer comprises one of: an oxide, including ZnO, ZnSnO, CdSnO, GaSnO, TlSnO, InGaZnO, CuAlO, SrCuO or LaCuOS; a nitride including GaN, InGaN, AlGaN or InGaAlN; a carbide including SiC: and diamond.

8. The OLED as claimed in claim 5 , wherein the gate electrode and the source and drain electrode comprise one of Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO) and Indium Tin Zinc Oxide (ITZO).

9. The OLED as claimed in claim 1 , wherein the organic light, emitting device comprises a first electrode layer, an emission layer and a second electrode layer.

10. The OLED as claimed in claim 9 , wherein the first electrode layer and the second electrode layer comprise transparent electrodes.

11. The OLED as claimed in claim 10 , wherein the first electrode layer and the second electrode layer comprise one of ITO, IZO and ITZO.

12. The OLED as claimed in claim 1 , wherein the organic light emitting device effects two sided emission.

13. A method of fabricating the Organic Light Emitting Display (OLED) defined by claim 1 , the method comprising:

forming a photochromatic layer on a first surface of a transparent substrate;

forming at least one transparent Thin Film Transistor (TFT) on a second surface of the transparent substrate, the first surface of the transparent substrate and the second surface of the transparent substrate being on opposite sides of the transparent substrate; and

forming an organic light emitting device on the transparent TFT and electrically connecting the organic light emitting device to the transparent TFT.

14. The method as claimed in claim 12 , wherein the photochromatic layer is formed by a sol-gel method.

15. An OLED fabricated according to the process of claim 13 , wherein the photochromatic layer comprises at least one of an inorganic material, an organic material and a glass material that visibly changes in response to light.

16. An OLED fabricated according to the method of claim 13 , wherein the photochromatic layer comprises a borosilicate containing either Ag or halogen compound crystals.

17. An OLED fabricated according to the method of claim 13 , wherein the transparent TFT comprises a semiconductor layer, a gate electrode, and source and drain electrodes.

18. An OLED fabricated according to the method of claim 13 , wherein the semiconductor layer comprises a material having a wide band gap of at least 3.0 eV.