Micro LED and OLED in Taiwan - solid state lightingtssl

Taiwan International Conference on solid state lighting (TSSL2016), from April 13, 2016 to April 14th at Nangang Exhibition Hall conference room, focused on the two candidate future solid-state lighting: "LED" and "OLED", a number of industry and academic experts to share, including equipment, process, materials to the latest advances in design, which is more the three relates to show the application of new technology of "Micro LED", LEDinside OLED and Micro LED key summarized as follows:

Taiwan International Conference on solid state lighting, focused on the two candidate future solid-state lighting: "LED" and "OLED", a number of industry and academic experts to share, including equipment, processes, materials to design the latest progress. (photo: LEDinside)

OLED lighting business opportunities

OLED's development in recent years, not only in the display like a raging fire in lighting applications, more and more mature, Philips, LG, OSRAM and Central University described the design and application of OLED greatly, marketing OLED in general lighting, commercial lighting (hospital, Museum), the excellent performance of the taillights, OLED is a soft surface so light, no glare, low damage, blue spectrum is close to natural light, flexible characteristics also increase flexibility and imagination design, various features of the OLED lighting and LED lighting market made the difference, take preference of surface light source.

Key challenges for the commercialization of OLED:

(1) the price is expensive, the evaporation process yield to increase the material utilization rate of less than 10%, resulting in OLED panel prices, manufacturing process and material supply chain are actively so the development of printing, the Spin-Coating distance commercialization is still far away, while Ink-jetPrinting has been gradually forming, Merck, Konica Minolta and Aixtron are put forward in materials, equipment and processes as well as to enhance the luminous efficiency of the solution and the green and red emitting layer are significantly improved, printing material life Merck launched (LT95) has come to 8500 (Lv Guang) and 10000 hours (Hong Guang).

(2) blue phosphorescent still lacks a stable and efficient material.

(3) the light extraction efficiency (LEE), Yamagata University OLED pointed out that the general planar structure of LEE is about 20-25%, but through structural optimization such as ETL (electron transport layer), the new micro lens layer thickening method, LEE can be raised to 66%, is expected to be the luminous efficiency of OLED further increased to 160lm/W a direct challenge to the luminous efficiency of LED lighting.

(photo: LEDinside)

Micro LED will be the next killer technology in the LED industry

The University of Dezhou, Leti (Texas Tech University) and PlayNitride microLED all show their research results in the seminar, micro LED is a LED display and evolutionary applications, using epitaxial technology to make the size and pitch are in the micron grade ultra small LED, after the substrate transfer and color conversion, do pixel level control self luminous display in other words, that is "super small spacing" and "free package" and "consumer applications" version of the LED display. Micro LED and the recent red OLED as a self luminous display, which is the "inorganic" and "organic" light source in the panel cell direct confrontation.

(photo: PlayNitride)

MicroLED achieve true LED Display

The light utilization efficiency is very poor, after the backlight backlight module, polarizer, TFT, LCD, color filter, the remaining light is often less than 10%, plus the backlight in constant light condition, resulting in reduced contrast (liquid crystal light leakage problem) and the energy consumption is not efficiency, even in wide color gamut and LED the design surface to find a solution, but the essence is still the LCD backlight, the efficiency and speed of response to natural and self luminous display (such as OLED) competition, so when the display technology to the LCD era ", micro LED LED will be turned back to its source, shows an important weapon in the market, is also the true meaning the" LED display".

How to drive each pixel as a key challenge

To drive the micron level of LED is very difficult, which is why LCD needs to achieve high PPI LCD pixel control, development of micro LED in addition to epitaxial barrier, focuses on the driving circuit and the color change, small size is Flip Chip will be sent to the CMOS light source combined with silicon substrate to do electrical connection, however the size of display, "Mass Transfer micro LED display" became the key, whether it is transferred to TFT blue chip, and then realize the color conversion quantum dot, nano materials, or batch will transfer R and G, Bchip from the long crystal substrate to the driver circuit, are in need of Technology transfer alignment is very accurate, so PlayNitride CEO Li Yunli said: "Mass Transfer of micro LED is art".

Current status and development of Micro LED Technology

Leti in the seminar introduces iLED matrix, Blu ray (440nm) EQE9.5%, brightness up to 107Cd/m2, green EQE5.9%, brightness up to 108Cd/m2, using quantum dots to achieve full-color display, Pitch only 10um, future goals do 1um, Leti short-range plans to cut from the smart lighting, in the process of (2-3) HUD and HMD to enter the market, grab a VR/AR thermal remote target (10 years) into large size display application.

Taiwan on behalf of the PlayNitride for the first time published a long time low-key development of PixeLED TM display technology, the same as the basis of gallium nitride, transferred through the transfer of technology to the panel, transfer yield has reached 99%! In addition, PixeLED TM display power consumption is only 10% of the general LCD, OLED of 50%. Based on the above, it can be seen that micro LED has the advantages of high illumination, low energy consumption and high resolution