STTR Phase I: Innovating Micro-Light Emitting Diode (LED) Manufacturing with Novel Quantum Dot Micro-Patterning Technology

This Small Business Technology Transfer (STTR) Phase I project focusses on chip manufacturing to create micro-Light Emitting Diodes (LEDs). Micro-LEDs are semiconductor chips devices that emit light when an electric current passes through them. Micro-LEDs will benefit virtual- and augmented-reality (VR/AR) technologies. VR/AR are immersive technologies that have revolutionized the way we interact with digital information and the physical world. VR/AR displays are in dire need of innovative optical technologies to achieve widespread availability and accessibility across various platforms and locations. Applications where the displays are closer to the eyes are very expensive due to the need for high resolution images with sufficient brightness in a compact form. Micro-LED displays are a leading solution, but current chip manufacturing is low-yield and cost prohibitive for consumer-grade devices. This project will provide an innovative process to overcome many chip manufacturing obstacles through the use of micro-patterned quantum-dot (QD) color converters. The process is simpler, significantly cheaper, and compatible with standard semiconductor manufacturing already employed by industry. This Small Business Technology Transfer (STTR) Phase I project will investigate the use of micro-patterned QD color converters to mitigate the need for pick-and-place assembly of red, green, and blue micro-LEDs. The current state of the art, a pick-and-place method, has severe limitations and insufficient yield. The goal is picking and placing millions of sub-pixels from epitaxial wafers with nearly zero defects. This problem is a top contributor to the overall cost for micro-LEDs today. This technology will take a different approach to achieve full color with high resolution. It will use color converters to reduce the number of steps by orders of magnitude, through only one lift-off process. For VR, the display resolution must be >1000 pixels-per-inch, which can be challenging to achieve via standard approaches. For AR, the requirements are even higher. The new process will achieve extremely high resolution and will be suitable for a wide range of color conversion materials, including most common QDs. The technology also has the essential benefit that unused QDs can be recycled and reused. The outcome from this STTR Phase I project will be a prototype demonstrating the viability of the method to produce high-resolution QD patterns on a static backplane. 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.