PFI-TT: Development of a low-cost OLED via surface chemistry

The broader impact/commercial potential of this Partnerships for Innovation - Technology Translation (PFI-TT) project is greater availability of the superior (but currently more expensive) organic light emitting diodes (OLEDs). OLEDs display advantages including high brightness, large viewing angles, thin profile, lightweight and flexible construction, and custom form factors. The cost savings achieved via the project potentially allows these OLEDs to enter lower cost markets currently occupied by liquid crystal displays (LCD, e.g. calculators, monitors), providing higher quality displays at comparable cost. Lower cost flexible OLEDs accelerate their adoption in next generation devices such as smart fabrics, rollable/foldable electronics, and bioelectronics. Reduced cost in OLEDs also directly benefits consumers of electronic devices which already contain these screens (e.g., OLED TVs, smartphones, and tablets).The proposed project seeks to address an issue that occurs during the last step of the OLED stack manufacturing process. This step deposits hot or high energy metal electrodes onto the sensitive organic layers leading to material damage and/or formation of metal filaments shorting the device. As an alternative, a thin chemical coating, only a nanometer thick, can be applied to the surface of the top organic layer. Chemical substituents are designed to specifically bind to the incoming metal, arresting its penetration into the sensitive organic layers and eliminating damage. By controlling this interface, less organic material is needed to compensate for the damage-induced inefficiencies. These reduced cost OLED prototypes are fabricated and assessed via standard device metrics (e.g., device driving voltage, external quantum efficiency, and lifetime) to show device performance is maintained. Coating conditions are optimized within industrially-compatible tools (atomic layer deposition) with a processing time and thermal budget in line with manufacturing requirements. The anticipated outputs of this research are a technology which can be immediately implemented by existing display manufacturers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.