1. Field of the Invention
The present invention relates to an active matrix electroluminescent device, and more particularly, to a top-emission active matrix electroluminescent device.
2. Description of the Related Art
Electroluminescent display devices are active display devices that have many advantages over cathode-ray tubes (CRTs) or liquid crystal displays (LCDs). For example, an electroluminescent display device typically has a wide viewing angle, high brightness and contrast, high response speed, light weight, small size, thin thickness, and low power consumption. FIG. 1A is a schematic cross-sectional view showing the partial structure of a conventional top-emission active matrix electroluminescent device corresponding to a pixel area. The conventional electroluminescent device mainly comprises, from top to bottom: a transparent cathode layer 101, an electroluminescent layer 102, a transparent anode layer 103, a metallic reflective layer 104, a passivation layer 105, a dielectric layer 106, an insulating layer 107, a driving thin-film transistor (TFT) 108, and a bottom substrate 100. The driving TFT 108 is located between the dielectric layer 106 and the bottom substrate 100. Referring to FIG. 1B, some of the light emitted from the electroluminescent layer 102 is respectively reflected by the transparent cathode layer 101, the electroluminescent layer 102 where light emission occurs, and the transparent anode layer 103. This produces a micro-cavity effect between the transparent cathode layer 101 and the transparent anode layer 103. On one hand, the micro-cavity effect improves emission luminance of the conventional electroluminescent device, and on the other hand, it results in color shift at different viewing angles, which is a serious drawback with the conventional electroluminescent device.
USPTO Backgrounds
USPTO Backgrounds