Active Matrix Organic Light-Emitting Diode (AMOLED) display technology has emerged as the most efficient technology over the other existing display technologies due to their fast response time, super-slim, lightweight nature, mechanical flexibility, wide color gamut, and high contrast ratio. OLED display technology is increasingly adopted in TV, smartphones, micro-OLED displays, and wearable device applications. Typically, each pixel of a smartphone display consists of red (R), green (G), and blue (B) OLEDs, also called sub-pixel, with feature sizes ~ 20-30 microns for 600 pixel per inch (ppi) display. Thus deposition and patterning of the organic emitting materials are the two key processes of interest. Traditional photolithography processes cannot be used for patterning organic emitting layers due to the incompatibility of organic materials with standard photolithographic conditions. Currently, vacuum thermal evaporation (VTE) of organic materials through the fine metal mask (FMM) is widely adopted in the OLED display industry.

A key development issue for the next-generation OLED technology is the implementation of Ultra-High Definition (UHD) displays for Virtual Reality (VR) devices application, which is typically four times higher resolution than HD displays with feature sizes of around 5-6 microns. The current FMM patterning technique cannot be implemented in UHD display due to the high coefficient of thermal expansion of FMM and shadowing effect, leading to a resolution limit of 550-600 ppi, which is suitable up to mobile displays. There have been several alternative approaches that are being developed to overcome these challenges. One of the promising approaches is the close-space-sublimation (CSS) of the organic emitter from a specially-designed donor substrate using laser-induced selective film transfer. This approach can solve both the scalability and resolution issues comfortably. The details of the existing VTE and FMM technology and the proposed mask-less transfer of patterned organic layer, along with fabrication scheme for specially-designed donor substrate, will be discussed in this research proposal seminar.