SmartKem has designed a tru-FLEX based all-organic five-stage OTFT ring oscillator using solution coating that operates with an oscillation frequency above 500kHz and stage delay of less than 200ns. This is the highest frequency reported to date for a unipolar ring oscillator fabricated using a solution processed organic semiconductor and gate dielectric. It is also expected that with further optimisation of the circuit design, oscillator frequencies above 1MHz can be attained.
This result is said to open the door to a range of application possibilities. For instance with the emergence of the IoT, one market requirement that SmartKem says has not been met is for low cost, thin, flexible and disposable RFID and NFC tags for the transmission of data from devices, sensors or objects. To achieve the necessary bit rate of 53kbits/s for a RFID or NFC device operating at the standardised frequency of 13.6MHz, a stage gate delay in the logic of less than 400ns is needed. SmartKem’s ring oscillator operates below this requirement, making it suitable as a platform technology for fully printed, low cost, flexible electronics.
A more immediate application is as a TFT backplane platform for the manufacture of conformal LCD and flexible AMOLED displays. Narrow bezels can now be achieved by the use of ‘integrated gate drivers’ fabricated on the display backplane. Whilst it was once thought that this could only be achieved using inorganic materials such as LTPS, these result shows that SmartKem’s tru-FLEX could allow the manufacture of integrated gate drivers that would not only drive 4K2K displays but, would also offer physical flexibility.
Steve Kelly, CEO and founder of SmartKem, said: “This emphasises the enabling nature of materials innovation in driving forward the potential of flexible electronics, not just for applications in smart, flexible electronics for the Internet of Things, but also the unique position it holds in enabling the growth of the flexible display industry.”
Kelly claims that the solution coated tru-FLEX TFT platform can be adopted into existing display TFT backplane production lines commonly used by manufacturers in Asia without the need for any new equipment.
