74‐1: 31″ Flexible Printed OLED TV Display Technology: It's TV Mobiles

Abstract

The flexible printed OLED TV display technology will be able to create new application market, such as rollable/foldable TV, in the future. It's TV Mobiles. Recently, the TCL (Guangdong Juhua Printed Display Technology Ltd. Co, TCL CSOT & TCL Corporate Research) has successfully demonstrated the 31″ FHD flexible printed OLED TV in CES 2020. The product is fabricated by ink jet printing technology with top emission OLED device architecture, advanced encapsulation technology and is driven by IGZO oxide TFT B/P technology. The panel performance of 31″ flexible printed OLED TV has continuously improved drastically after demonstration at CES based on optimization of top emission OLED device architecture including printing OLED material development, MURA free printing technology, Oxide TFT B/P technology and advanced thin film encapsulation technology. The RGB device performance of 31” FHD flexible printed OLED TV has high current efficiency and long‐life time, R:(0.68,0.32), 46.3cd/A, LT95>8khrs@1knits, G:(0.28,0.70),115.5cd/A, LT95>6khrs@1knits, B:(0.13,0.062),5.35cd/A, LT95 >0.35khrs@1knits respectively. It is getting closer and closer to meet the commercial requirement of flexible OLED TV target specification. The technical challenges of 31″ FHD flexible printed OLED TV are also identified. In this paper, the technology development status and technical challenges are discussed

MoS2-Thin Film Transistor Based Flexible 2T1C Driving Circuits for Active-Matrix Displays

“…In Figure f, the calculated carrier mobility average 52.8 cm 2 V –1 s –1 , and the maximum mobility reaches 75 cm 2 V –1 s –1 . When compared to TFTs based on indium gallium zinc oxide (IGZO), − ,− organics, − ,− CNTs, and previous MoS 2 ,− employed in flexible displays (refer to Table ), our results demonstrate the highest mobility, which is crucial to the display performance in terms of offering faster switching and reduced response time on the image quality. Besides, these devices also exhibit high on-state currents of 0.9 mA and large on/off ratio (average 1.5 × 10 8 , Figure g).…”

“…In flexible displays, semiconductors are utilized as the active layer of back-plane thin film transistors (TFTs). Conventional semiconductors such as amorphous or polycrystalline silicon and metal oxides can be used for fabrication of flexible TFTs but usually exhibit a trade-off in performance as compared to their rigid counterparts. − In contrast, organic semiconductors, semiconducting carbon nanotubes (CNTs), and emergent two-dimensional (2D) semiconductors are very promising candidates due to their intrinsic mechanical flexibility. Organic TFTs are usually reported to have good flexibility yet poor performance, as well as incompatibility with standard microfabrication techniques. − CNT and 2D-semiconductor TFTs are considered to offer competitive performance compared with conventional semiconductors for high-end applications, although many technological challenges are waiting to be overcome. − …”

Flexible Printed OLED TV has Potential to Create a New Application Market

“…Table 1 compares the product performance of these three technologies in terms of device architecture for flexible printed displays, 8K high‐resolution capability, image quality, and cost competitiveness. RGB printing technology 1,5–8 has multiple benefits in terms of flexible display capability, because the simple device architecture with only five to six layers easily can enable the neutral plane for bending reliability (compared to WOLED + CF that contains more than 20 organic layers and QD‐OLED that consists of a blue OLED tandem device architecture, color‐conversion red and green QD layers with a RGB color filter layer, and requires two rounds of the encapsulation process). The 8K high‐resolution capability easily adopts the top‐emission device architecture without cathode infrared (IR) drop issues, which can maximize the aperture ratio and the capability to make an 8K (276 ppi) high‐resolution OLED TV with new pixel design at more than 32 inches.…”

8.1: Invited Paper: 17‐inch Flexible IGZO OLED Display by Ink‐jet Printing Method

“…The flexible ink-jet printed OLED driven by IGZO-TFT backplane is promising way for industrial production taking advantage of low manufacturing cost [3,4] . However, there are facing a lot of challenges to meet the requirements of commercial flexible printed displays including the high image quality with precise compensation technology, the elaborate ink-jet printing (IJP) technology, the stability flexible IGZO backplane and encapsulation technology [5,6] . TCL CSOT has labored hard and long on the IJP OLED displays.…”