1. Field of the Invention
The present invention relates to a display device and a method of manufacturing the same.
2. Description of the Related Art
Display devices are devices that visually display data. Examples of the display devices include liquid crystal displays, electrophoretic displays, organic light-emitting displays, inorganic electroluminescent displays, field emission displays, surface-conduction electron-emitter displays, plasma displays, and cathode ray displays.
Of the above display devices, organic light-emitting displays have superior viewing angles and contrast ratios because they are self-luminous, can be made light and thin because they do not require backlight, and are advantageous in terms of power consumption. In addition, the organic light-emitting displays can be driven at direct current (DC) low voltages, have fast response speed, and are advantageous particularly in terms of manufacturing costs. Generally, an organic light-emitting display has a structure in which an anode, an organic layer and a cathode are sequentially stacked on a substrate on which a pixel circuit such as a thin-film transistor is formed.
The emission structure of such an organic light-emitting display may be divided into a resonance structure and a non-resonance structure according to whether light is resonated. In the resonance structure, light emitted from an organic layer exits the organic light-emitting display after being resonated within the organic light-emitting display. In the non-resonance structure, light emitted from the organic layer exits the organic light-emitting display without being resonated within the organic light-emitting display.
An organic light-emitting display having the resonance structure needs to satisfy different resonance conditions individually for different colors. For example, in the organic light-emitting display having the resonance structure, organic layers respectively emitting red light, green light and blue light should have different thicknesses. In the organic light-emitting display having the resonance structure, each organic layer should be deposited using an independent mask. This complicates the process and increases manufacturing costs.
Unlike the organic light-emitting display having the resonance structure, an organic light-emitting display having the non-resonance structure can be manufactured in a simple process and at a low cost.
The organic light-emitting display having the non-resonance structure may include a scattering structure. The scattering structure scatters light emitted from an organic layer, thereby preventing the occurrence of resonance within the organic light-emitting display.
The scattering structure may be formed using agglomeration properties of silver (Ag). In an example, the scattering structure may be formed using silver crystal particles formed by high-temperature heat treatment as a scattering lens. In another example, the scattering structure may be formed by sequentially depositing tungsten oxide and silver and then patterning the tungsten oxide using silver crystal particles formed by high-temperature heat treatment as an etch mask.
However, it is difficult to control the size and density of silver crystal particles formed by agglomeration of silver. In addition, due to low chemical resistance of the silver, it is difficult to perform a process in a state where the silver is exposed. Further, since it is difficult to develop an etchant that can selectively etch the tungsten oxide, it is difficult to pattern the tungsten oxide as desired.
USPTO Backgrounds
USPTO Backgrounds