SBIR Phase I: High Light-Throughput Electrodes for Top-Emitting and Transparent OLED Displays

The broader/commercial impact of this Small Business Innovation Research Phase I project is the generation of more efficient and brighter organic light emitting diodes (OLEDs) which are the individual lighting emitting elements within the displays of our cell phones, tablets, and smart watches. This project seeks to provide the same quality of OLED display but at 1.5 higher efficiency, thereby allowing a phone, for example, to run at 11% less power, with potential savings as high as 19%.

If one considers the power used by the 4.9 billion cell phones worldwide (equivalent to the power generation for the state of Delaware) the cumulative saved power provides a significant effect in aggregate. Beyond large aggregate energy savings, this project provides other benefits to the end consumer. These include better brightness for outdoor usage of phones/watches/tablets, better viewing in augmented reality or virtual reality headsets, and even potential improvements in see-through display applications.

The efficient and brighter OLEDs are enabled by the project’s ultra-thin chemical adlayer which is placed on top of the materials in the OLED stack, resulting in superior transparency of the top-laying metal electrode. This circumvents the problem that has long vexed OLED display manufacturers, specifically, that the thin metal electrode providing electrical current to the materials in the OLED stack needs to be both transparent and conductive.

Normally, reducing the thickness of the electrode improves transparency, but severely diminishes conductivity. As such, this thin metal cannot be reduced any further, and still limits the amount of light that can pass from the OLED. The project avoids this issue by making the metal a more uniform (continuous) layer by reducing self-aggregation of the metal, allowing the metal to retain high conductivity at a much lower thickness.

This effect is enabled by the project’s technology, which is an unusually effective nucleation inducer. The project validates the effectiveness of the chemical adlayer in OLED pixels and then optimizes chemical structure for increased effectiveness. The resultant chemical treatment is then capable of reaching the targeted metric of 1.5 more efficient/brightness OLED pixel.

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.