A prototype active-matrix OLED using graphene anode for flexible display application (original) (raw)

Recently, significant progress has been made toward application of organic (small molecule/polymer) lightemitting diodes (OLEDs) in full color flat panel displays and other devices. However, current technologies for OLEDs in the market are still very limited, especially in terms of cost, size and flexibility. We believe fabricating OLED displays using roll-to-roll (R2R) manufacturing on plastic is the way to achieve low cost, light weight and flexibility. One of big challenges for fabricating flexible OLED displays is alignment on large area flexible substrates. We discuss here a proof-of-concept HP proprietary solution to fabricate flexible active matrix OLED displays, which involves a process in which a welldefined micro OLEDs (μOLEDs) frontplane is directly laminated with our R2R processed active matrix flexible backplane built via self-aligned imprint lithography (SAIL) without any in-between alignment. A proof-of-concept AMOLED device has been built, which contains a flexible μ...

Graphene has attracted considerable interest as a prospective material for future electronics and opto-electronics. Here, the synthesis process of large area few layers graphene by Atmospheric Pressure Chemical Vapor Deposition (APCVD) technique is demonstrated. Quality assessments of graphene are performed and confirmed by Raman analysis and optical spectroscopy. Next, graphene was transferred on Polyethylene Terephthalate (PET) substrates and implemented as transparent conductive electrode in flexible Polymer Dispersed Liquid Crystal (PDLC) devices. Their electro-optical properties, such as voltage-dependent transmittance and flexibility behavior are measured and discussed. The stability of the sheet resistance after 1200 bending tests of graphene/PET structure is demonstrated. The obtained results open a great potential of graphene integration into the next generation Indium Tin Oxide (ITO) free flexible and stretchable optoelectronics.

The mechanical behavior of a prototype touch panel display, which consists of two layers of CVD graphene embedded into PET films, is investigated in tension and under contact-stress dynamic loading. In both cases, laser Raman spectroscopy was employed to assess the stress transfer efficiency of the embedded graphene layers. The tensile behavior was found to be governed by the “island-like” microstructure of the CVD graphene, and the stress transfer efficiency was dependent on the size of graphene “islands” but also on the yielding behavior of PET at relatively high strains. Finally, the fatigue tests, which simulate real operation conditions, showed that the maximum temperature gradient developed at the point of “finger” contact after 80 000 cycles does not exceed the glass transition temperature of the PET matrix. The effect of these results on future product development and the design of new graphene-based displays are discussed