DEUS

Two major advances give strong credibility that a scientific and technological revolution is at hand with both ultra-fast organic optoelectronics and organic photonic above integrated circuits: 1- the recent demonstration of sub-ns and -ps optical responses in high-speed organic light emitting diode (HS-µ-OLED) resulting from the combination of microwave techniques with organic heterostructures and, 2- the easy heterogeneous integration of OLED on silicon as in organic microdisplays. To evaluate these promises and investigate if HS-µ-OLEDs constitute a valuable alternative to Gallium Nitride microLED, the DEµS project aims at fabricating an integrated ultra-fast organic device for light communications. It is proposed to 1- fabricate monolithic top-emission HS-µ-OLEDs on silicon as data emitters and, 2- implement enhanced waveform modulations of single HS-µ-OLEDs and innovative Digital-to-Optical architectures with HS-µ-OLED matrices to target 10+Gbit/s data rates. This will be reached considering the three main following objectives. First, a 10-fold enhancement of the state-of-the-art time response is targeted for light communication. At the material level, a screening of available fast fluorescent small molecules will lead to pre-qualified materials, operating in visible wavelengths but possibly also in near infrared spectrum. At the device level, in order to minimize electroluminescence lifetime further, two new paradigms for the design of high-speed organic heterostructures will be addressed: the dynamical spatial distribution of polarons within the heterostructures will be studied to identify the conditions on the layer thicknesses for which the distribution of both types of polarons is maximized exactly in the recombination/emitting layer during the pulse; then the optimal operating conditions will be identified by underlying the important role of the Langevin recombination rate in the dynamical response of OLED. The second main objective will focus on innovative processes for monolithic integration on Silicon circuits for single and multiple (matrix arrangement) HS-µ-OLEDs with a top-emission (TE) architecture. HS-µ-OLEDs with CoPlanar Wave-guided electrodes will be integrated on Silicon substrates, a world premiere. Si substrates will be used for its better heat dissipation and for the purpose of the targeted monolithic integration. Also, optimal weak microcavity effects will be engineered leading to a possible control of the electro-luminescence lifetime. The third objective deals with the implementation of enhanced modulation waveforms on single HS-µ-OLEDs and innovative Digital-to-Optical architectures on HS-µ-OLED matrices. Simple and complex intensity modulation will be designed and implemented on single HS-µ-OLEDs for real-time hardware-in-the-loop optical wireless transmissions, reaching up to 10 Gb/s. Finally, at the system level, we will develop and test original architectures of HS-µ-OLED matrices. Digital-to-analogue in conventional LC systems will be removed and innovative Digital-to-Optical waveforms and architectures will be designed by driving each HS-µ-OLEDs of the matrices directly with the quantized waveforms. This final objective will take benefit from both the high-speed capacities of each pixel and the easy and low-cost integration of these HS-µ-OLEDs on Si. In parallel, DEµS project will also address a degradation mechanisms analysis by stressing and ageing the HS-µ-OLED under both DC and high frequency excitations over long periods of time. This degradation analysis will be derived and modeled at all stages of the design (material, device and system) in order to guarantee the integration of HS-µ-OLEDs in viable products. In conclusion, we truly believe a revolution is at hand with ultra-fast organic optoelectronics currently being unveiled to be as fast as inorganic optoelectronics but potentially faster, and the DEµS consortium gathers the most suitable French partners to make this happen.