1. Field
One or more embodiments described herein relate to a display device.
2. Description of the Related Art
An organic light emitting diode (OLED) display uses a plurality of pixels to generate images. Each pixel includes an organic light emitting layer between an anode and cathode. Electrons injected from the cathode and holes injected from the anode combine in the organic light emitting layer to form excitons. Light is emitted when the excitons transition from an excited state to a stable or ground state.
A variety of methods have been proposed for making an OLED display. One approach uses a laser to form color (e.g., red, green, and blue) light emitting layers for corresponding pixels. This approach is often referred to as laser-induced thermal imaging (LITI).
During the LITI method, a laser beam is irradiated through a mask pattern on a donor film. The donor film is formed of a base film and transfer layer. When irradiated, the mask pattern is transferred through the transfer layer to form a light emission layer. Through this method, each emission layer may be finely patterned. Also, the LITI method is a dry process which may prove to be beneficial in some applications.
However, the LITI method is not without drawbacks. For example, during fabrication, the donor film is disposed on and bonded to a substrate. During vacuum bonding, the donor film may move or shift in position. More specifically, when an organic material of the donor film is transferred to a protruded portion during bonding, the organic material may shift in position and/or may not remain on the donor film. When the donor film moves toward the light emitting region, the organic material may not be transferred to the light emitting region. As a result, a defective pixel may be formed.