Periodic Reporting for period 2 - POSEIDON (NanoPhOtonic devices applying SElf-assembled colloIDs for novel ON-chip light sources)
Reporting period: 2021-01-01 to 2022-06-30
The aim of POSEIDON is to develop a radically new bottom-up approach toward multi-scale, on-chip self-assembly of active colloids based on low-cost colloid technology. For the first time this encompasses the entire process chain of computer-aided design, controlled synthesis, hierarchical assembly, optoelectronic integration and device fabrication. By controlling and designing self-assembly processes directly on a device, addressing length scales from nm to 100’s of μm simultaneously, the POSEIDON approach allows to fabricate functional nanophotonic components with 3D, single-nm resolution integrated into complex PICs. The goal of POSEIDON is to develop electrically pumped light sources that can be monolithically integrated into the back end of CMOS chips. So far, the key bottleneck that is holding back integrated photonic applications is the lack of a monolithically integrable, mass-manufacturable light source because Si does not emit light efficiently. All top-down approaches of heterogeneous integration of III-V light sources are costly, have low integration density and low throughput, creating massive cost and complexity barriers for the application and commercialization of Si photonics in general and PICs in particular. Packaging costs including fibers for external light sources currently constitute around 80% of the total cost of Si photonic PICs and are hence a showstopper for many applications. The breakthrough targeted by POSEIDON overcomes the limitations of top-down PIC fabrication and tears down the massive cost and complexity barriers initially mentioned. The developed technology will enable further applications from optical computing, to quantum optics for ultra-secure communications, to personalized health monitoring devices able to detect molecules at ultralow concentrations. The aim of POSEIDON is to develop a radically new approach toward multi-length-scale, on-chip assembly of active colloids for the creation of on-chip light sources.
WP1: Within the WP1 Theoretical design of colloidal light sources, the roadmap of nanoantennas for the light source was identified and selected. The activities focused on nanorod gap antennas, as an optimal structure to accomplish the objectives of the POSEIDON project. The study of multishell nanoparticles to obtain zero-index-materials (ZIMs), and the effectiveness of the ZIMs as a perfect coupler between an emitter-nanoantena system and a waveguide was assessed. The conclusion so far is that the required particles are too large for this task and our focus is shifted to the other configurations.
WP2: Synthesis of colloidal building blocks: Development of particle synthesis protocols for polystyrene and PDVB laytex particles by miniemulsion and classical emulsion polymerization was completed. Synthesis of new RAFT polymers from different monomer systems for modification of quantum dots (QDs) and gold (Au) nanoparticles (NPs) were completed. Modification of QDs with RAFT polymer for particle transfer from organic apolar to aqueous medium was successful. Synthesis of metal nanoparticles for nanoantenna light sources was completed with final evaluation that refers to the synthesis of nanoparticle building blocks for the fabrication of nanoantenna light sources (in agreement with simulation results from WP1).
WP3: Integrated assembly of colloidal light sources has focused on the theoretical design of such materials and identified core-shell particle assemblies as a promising avenue. There has been excellent progress in the self-assembly of nanoantenna structures. The consortium has agreed on four distinct strategies as outlined in WP1. All strategies are subjected to rigorous examination, both in terms of synthetic feasibility and theoretical assessment of emission enhancement. To this point, dimer nanoantennas and patch nanoantennas have emerged as feasible candidates. As a side aspect with potential relevance to tailor emission properties, we successfully prepared chiral nanoantenna arrays that exhibit chiroptical properties. We are 100% capable of producing crescent shape and disk shape gold nano-antennas.
WP4: Creation of electrically pumped light source: The main structures were developed and their characterization is ongoing. More nanoantenna structures need to be evaluated to extract the efficiency and directionality of the light emission. Integrating monolayer QDs and nanoparticles on an optimized photonic chip fabricated by AMO to create electrically pumped nano-antennas was completed. Activities in this WP were also focused on exploring new nano-antennas, blocking layers etc. for reducing electrical junction breakdown and enhancing emission efficiencies of the electrically pumped nanoantennas.
WP5: Creation and optimization of PIC: The fabrication runs so far have been successful with satisfactory preliminary results. Gaps for improvements have been identified and are being addressed. New proposed process flows are a good direction to reach the project goals and will soon be fully evaluated. All the necessary basic calculations of particle-on-mirror configuration have been completed by AMO. The process margin was verified. Additionally, we have identified few more configurations, which might increase the coupling efficiency. The necessary data will be discussed with CSIC to perform further simulations. Currently, we are one step away (QD+Au NPs) to form the first generation of the integrated optically pumped light source.
WP6: Dissemination & Exploitation: Mid-term report on dissemination and the second version of the exploitation plan was prepared. Several communication materials have been created: logo & templates, factsheet, press release, the LinkedIn page with the growing number of followers (156 followers), business cards (with QR code link to website), the website that was visited by 4000 users during Jan 2021-June 2022.
WP7: Project Management & coordination: Three high-level project meetings have been held (M18, M24, and M30 meeting) and an EC review meeting in month 15. Additional monthly WP web conferences were organized and topic specific meetings took place in smaller groups.
WP2: Synthesis of colloidal building blocks: Development of particle synthesis protocols for polystyrene and PDVB laytex particles by miniemulsion and classical emulsion polymerization was completed. Synthesis of new RAFT polymers from different monomer systems for modification of quantum dots (QDs) and gold (Au) nanoparticles (NPs) were completed. Modification of QDs with RAFT polymer for particle transfer from organic apolar to aqueous medium was successful. Synthesis of metal nanoparticles for nanoantenna light sources was completed with final evaluation that refers to the synthesis of nanoparticle building blocks for the fabrication of nanoantenna light sources (in agreement with simulation results from WP1).
WP3: Integrated assembly of colloidal light sources has focused on the theoretical design of such materials and identified core-shell particle assemblies as a promising avenue. There has been excellent progress in the self-assembly of nanoantenna structures. The consortium has agreed on four distinct strategies as outlined in WP1. All strategies are subjected to rigorous examination, both in terms of synthetic feasibility and theoretical assessment of emission enhancement. To this point, dimer nanoantennas and patch nanoantennas have emerged as feasible candidates. As a side aspect with potential relevance to tailor emission properties, we successfully prepared chiral nanoantenna arrays that exhibit chiroptical properties. We are 100% capable of producing crescent shape and disk shape gold nano-antennas.
WP4: Creation of electrically pumped light source: The main structures were developed and their characterization is ongoing. More nanoantenna structures need to be evaluated to extract the efficiency and directionality of the light emission. Integrating monolayer QDs and nanoparticles on an optimized photonic chip fabricated by AMO to create electrically pumped nano-antennas was completed. Activities in this WP were also focused on exploring new nano-antennas, blocking layers etc. for reducing electrical junction breakdown and enhancing emission efficiencies of the electrically pumped nanoantennas.
WP5: Creation and optimization of PIC: The fabrication runs so far have been successful with satisfactory preliminary results. Gaps for improvements have been identified and are being addressed. New proposed process flows are a good direction to reach the project goals and will soon be fully evaluated. All the necessary basic calculations of particle-on-mirror configuration have been completed by AMO. The process margin was verified. Additionally, we have identified few more configurations, which might increase the coupling efficiency. The necessary data will be discussed with CSIC to perform further simulations. Currently, we are one step away (QD+Au NPs) to form the first generation of the integrated optically pumped light source.
WP6: Dissemination & Exploitation: Mid-term report on dissemination and the second version of the exploitation plan was prepared. Several communication materials have been created: logo & templates, factsheet, press release, the LinkedIn page with the growing number of followers (156 followers), business cards (with QR code link to website), the website that was visited by 4000 users during Jan 2021-June 2022.
WP7: Project Management & coordination: Three high-level project meetings have been held (M18, M24, and M30 meeting) and an EC review meeting in month 15. Additional monthly WP web conferences were organized and topic specific meetings took place in smaller groups.
The project is expected to create new applications and markets and reinforce leadership of European scientific and industrial players in the fields of e.g. optical communication, sensing and point-of-care medicine.
During the last two decades, integrated photonics based on silicon photonics have gained a lot of interest in research and industry developments. The rapid increase of data traffic makes drastic changes to more efficient technologies like full optical data transmission necessary. Recent developments in optical communication mainly rely on hybrid integration of III-V lasers on top of the silicon platform. This procedure is not only costly in terms of III-V wafers, but especially the assembly can reach up to 80% of the fabrication cost. Large scale integration of efficient (laser) light sources would open the field to many new applications such as point of care medicine, environmental sensing as well as quantum photonics. POSEIDON aims to test out different approaches for colloidal assembly focused on the integration on photonic chips. The two test scenarios are sensing and communication technologies. By defining ways to integrate light emitting materials efficiently onto the photonic platform, POSEIDON paves the route to a new age of photonic integrated circuits.
During the last two decades, integrated photonics based on silicon photonics have gained a lot of interest in research and industry developments. The rapid increase of data traffic makes drastic changes to more efficient technologies like full optical data transmission necessary. Recent developments in optical communication mainly rely on hybrid integration of III-V lasers on top of the silicon platform. This procedure is not only costly in terms of III-V wafers, but especially the assembly can reach up to 80% of the fabrication cost. Large scale integration of efficient (laser) light sources would open the field to many new applications such as point of care medicine, environmental sensing as well as quantum photonics. POSEIDON aims to test out different approaches for colloidal assembly focused on the integration on photonic chips. The two test scenarios are sensing and communication technologies. By defining ways to integrate light emitting materials efficiently onto the photonic platform, POSEIDON paves the route to a new age of photonic integrated circuits.