sony corporation has revealed their latest development, a super-flexible 80 μm-thick
4.1-inches 121 ppi organic thin film transistor (OTFT)*1-driven full color OLED display
which can be wrapped around a thin cylinder.

the display was achieved due to sony’s research of integration technologies of OTFTs
and OLEDs on a 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 from interfering
with the roll-up of the display) and soft organic insulators for all those in the integration circuit.
sony has created the organic semiconductor material, peri-xanthenoxanthene (PXX) derivative,
which is stable under exposure to oxygen, moisture, light and heat, with improved current
modulation of eight-times*2 that of conventional OTFT with organic semiconductor of pentacene.

by combining these technologies, they have successfully demonstrated the world’s first
OLED panel*3 with an integrated gate-driver circuit with OTFTs. the imporvement of the
OTFT makes it capable of reproducing moving images while being rolled-up repeatedly,
around a cylinder with a radius of 4mm. this roll-up capability is possible because the gate-driver
IC chips have been removed from the display. even after 1000 cycles of repeatedly rolling-up
and stretching the display, there was no clear degradation in its ability to reporudce moving images.
the material would be well suited to e-readers and other mobile devices that could have
large screens and small form factors

technology features
l: integration of flexible gate-driver circuit with OTFTs
r: the high performance OTFT with originally developed high-mobility and highly-stable organic semiconductor materials,
PXX derivatives

OTFT specifications:
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