While materials for organic light emitting diodes
(OLEDs) are getting better and better, and encouraging news about record-breaking parameters in efficacy and luminance were published quite recently. One of the major problems in flexible lighting and display devices is still unsolved: the lifetime of such devices is too short, and hence, customers are not ready to pay, no matter how impressive and elegant the systems may look.
The issue is in the light emitting materials themselves, namely in their intrinsic sensitivity against moisture and oxygen. The same is true for organic photovoltaics (OPV): despite promising results and potential low-cost fabrication methods, at least compared to crystalline
silicon, lifetime is not long enough even for less-demanding applications. Thin-film inorganic PV, e.g. based on amorphous silicon or CIGS or CdTe, is less sensitive, but again, manufacturers usually choke if asked for a twenty year guarantee if it comes to flexible or just bendable products.
Glass based devices perform much better in both cases of OLED and OPV, since the glass provides good barrier properties against those "enemies". For flexible, polymer based substrates, the situation is quite different, and special coatings and lamination techniques are required to protect the sensible organic materials.
IDTechEx is following the progress in this field closely, and at the next Printed Electronics
Asia conference dedicated to recent achievements and developments in the field of printed electronics, our specialist Dr Harry Zervos will give an update of what is going on and what is still needed. First-hand information will be provided by one of the leading companies in the field: Vitex Systems, based in California, produces flexible substrates with a special stack of layers, combining polymer and thin aluminium oxide layers. Results of tests in OLED and OPV devices will be explained, as well as an outlook regarding technical and cost developments.
Printed Electronics Asia will take place from September 30-October 1, with Masterclasses being held on September 29 and October 2 at the Sheraton Miyako Hotel in Tokyo, Japan. In addition, tours to local centres of excellence have been arranged, giving delegates a chance to see products and operations first hand.