New Technologies for Emerging Displays

The flexible and wearable displays featured with virtual reality and augmented reality will be next generation displaying needs. The current challenges for these emerging displays include fabricating flexible and high performance thin film transistors (TFTs), having wide range brightness from 0 to 10,000 nits, and patterning pixel size under 5 µm. To tackle these challenges, we developed electronically pure (6,5) single-walled carbon nanotube (SWCNT) as active materials of TFTs with transfer characteristics similar to those TFTs constructed on amorphous silicon, low-temperature polycrystalline silicon and metal oxides. Both N-type and P-type (6,5) SWCNT TFTs were fabricated with fA off-current and I_ON/I_OFF ratio of 10⁸. The (6,5) SWCNT inverter with voltage gain of 52 was also demonstrated by wire-bonding one P-type SWCNT TFT to one N-type SWCNT TFT. With the intrinsic flexibility and mechanic strength of SWCNTs, our electronically pure SWCNT could be the solution for flexible and high performance TFTs. We also demonstrated using aerosol jet printer to fully print (6,5) SWCNT TFTs, inverters, ring oscillators, and backplanes on plastics, glass and LED arrays. To have high aperture ratio for small pixel size, we recently developed electrolyte-gated organic light-emitting diodes in which the charge injection is modulated by external electric field through polymer electrolytes. We fabricated these GOLEDs using conjugated polymers and RGB phosphorescent small molecules as emitting layers and demonstrated the potential applications for displays.

Biography:

Dr. Huaping Li is the Chief Scientist at ATOM Nanoelectronics in charge of company operation, hiring and management, and technique challenges. Dr. Li is a professional scientist, raised and managed over $1M government funded projects through DoD and NSF. He has extensive experience managing and leading technical teams through SBIR/STTR projects. His research focus on carbon nanotube separation, carbon nanotube thin film transistor fabrication, printed electronics, advanced materials and gated OLED fabrication for emerging displays. Dr. Li received his B.S. from HuBei University in 1995 and M.S. from Chinese Academy of Sciences in 1998. Dr. Li was graduated from Clemson University with Ph.D. in Organic Chemistry in 2006, and trained as postdoctoral researcher at UCSB. Dr. Huaping Li is the primary inventor of 20 US/PCT patents. He also authored and co-authored over 50 articles, 1 book chapter and 20 conference papers.