Sony Corporation (‘Sony’) announced today that it developed a super-flexible 80 μm-thick 4.1-in 121 ppi OTFT*1-driven full color OLED display which can be wrapped around a thin cylinder.
To create the display, Sony developed OTFTs with an original organic semiconductor material (a PXX derivative) with eight times*2 the current modulation of conventional OTFTs. This was achived due to the development of integration technologies of OTFTs and OLEDs on an ultra-thin 20 μm thick flexible substrate (a flexible on-panel gate-driver circuit with OTFTs which is able to get rid of convetinal rigid driver IC chips interfering roll-up of a display) and soft organic insulators for all the insulators in the integration cuircuit. By combining these technologies, Sony successfully demonstrated the world’s first OLED panel*3 which is capable of reproducing moving images while being repeatly rolled-up – around a cylinder with a radius of 4 mm – and stretched.

Sony will proceed with the development of the solution / print based process which manufactures display devices from organic materials that are easily dissolved in common solvents. This process requires fewer steps, and consumes materials and energy more efficiently – thus has a smaller environmental footprint – compared to the conventional high temperature vacuum semiconductor process which use inorganic, silicon materials.

Sony will continue to improve the performance and reliability of its flexible organic displays because the application of these developments are expected to yield thin, light-weight, durable and mobile devices with enhanced form-factor.

Specification of the OTFT
organic semiconductor : peri-Xanthenoxanthene(PXX) derivative
hole mobility : 0.4 cm2/Vs
current on/off ratio : 106
channel length : 5μm
threshold voltage : -5V

Specification of the rollable OTFT-driven OLED display
size of a panel : 4.1 inch wide
number of pixels : 432 x 240 x RGB pixels
size of a pixel : 210μm x 210μm
resolution : 121 ppi (pixels per inch)
number of colors : 16,777,216
peak luminance : >100 cd/m2
contrast ratio : >1000:1
minimum bending radius : 4 mm
driving scheme : 2T-1C voltage programming with OTFTs
thickness of a panel : 80μm