Periodic Reporting for period 4 - COINFLIP (Coupled Organic Inorganic Nanostructures for Fast, Light-Induced Data Processing)
Reporting period: 2023-08-01 to 2024-07-31
COINFLIP seeks to make faster optical transceivers, which are crucial for every modern data-communication network, where they convert in-coming optical data from an optical fiber into electrical information to be processed by a computer end station. A central problem in this respect is that materials for processing optical data input must find a compromise between speed and sensitivity. In simple words, a material cannot be fast and sensitive to an incoming signal simultaneously because registering a very weak stimulus requires some time to process it. Therefore, COINFLIP merges one material, which is only fast, with a second material that is very sensitive (and slow). With this approach, we have developed materials that could convert light into electric information with a frequency of 0.23 GHz using an energy of only 27 fJ per bit of information transferred. We explored combinations of two-dimensional materials with thicknesses below 1 nm that exhibited data transfer times of 3 ps under laboratory conditions. If these conditions could be met in real devices, data transfer at several 100s GHz seems feasible with such optical transceivers.
We have tested a variety of different nanomaterials and explored their potential towards application in fast optical transceivers. This includes PbS, CuS and CdSe nanocrystals as well as Au nanoclusters. Most notably, we found that the surfaces of CdSe (https://arxiv.org/abs/1904.04752(opens in new window)) and CuS nanocrystals (https://arxiv.org/abs/1903.05037(opens in new window)) can be decorated with organic dyes to greatly expand their sensitivity for optical wavelengths which are typically not detected by these materials. In contrast, three-dimensional supercrystals of Au nanoclusters were found to exhibit highly interesting electric transport properties owing to the exceptionally large degree of long-range structural order (https://doi.org/10.1038/s41467-020-19461-x(opens in new window)) but they turned out to be chemically too unstable under intense light pulses. However, this discovery has enabled a follow-up study which utilizes this material for the cost-effective fabrication of electrical micro-circuits (https://doi.org/10.1002/smtd.202201221(opens in new window)). We have also explored the potential of Au nanorods for photodetection (https://doi.org/10.3390/nano13091466(opens in new window)). Following a similar idea, we have established a new method to print thin stripes of nanocrystal films onto electrical micro-circuits for further use as optical transceivers (https://arxiv.org/abs/2006.11202(opens in new window)). To complement the findings on optical transceivers based on nanocrystal/organic dye hybrid materials, we have detailed the interaction between these two material classes in experiment (https://arxiv.org/abs/2005.00898(opens in new window)) as well as with an extensive review of the field (https://doi.org/10.1002/anie.201916402(opens in new window)). We have designed optical transceivers based on CdSe nanocrystals and organic dyes with a 3dB bandwidth of 85 KHz (http://arxiv.org/abs/2109.02049(opens in new window)). We established that the maximum speed possible with state-of-the-art PbS nanocrystals is likely to be limited around 1 ns (https://doi.org/10.48550/arXiv.2112.11987(opens in new window)) highlighted pitfalls in accurately determining their speed (https://doi.org/10.48550/arXiv.2209.03676(opens in new window)) and we concluded our exploration of such nanocrystals coupled to organic dyes with a review of the field (https://doi.org/10.48550/arXiv.2202.06050(opens in new window)). We changed our focus material class to two-dimensional transition metal dichalocogenides and achieved a continuous development of the electrical bandwidth with such transceivers from 2.6 MHz for WSe2 (https://doi.org/10.48550/arXiv.2203.14053(opens in new window)) over 18 MHz for MoS2 (https://doi.org/10.1039/d3na00223c(opens in new window)) to >230 MHz for WSe2 (https://doi.org/10.1039/d4lf00019f(opens in new window)). We studied the electronic structure of MoS2 nanomaterials by spectroelectrochemistry (https://doi.org/10.1002/smll.202207101(opens in new window)) and monitored the effect of adsorbing organic dyes to their surface in this respect (https://doi.org/10.26434/chemrxiv-2024-4kc0h(opens in new window)) also with a special emphasis on the orientation of the molecules (https://doi.org/10.26434/chemrxiv-2023-tj7m0(opens in new window)). Combining transition metal dichalocogenides with black phosphorus enabled us to realize response times of 26 ps (https://doi.org/10.1038/s41467-024-49760-6(opens in new window)) which we recently even surpassed with a 3 ps response for combining WS2 with graphene (https://doi.org/10.26434/chemrxiv-2024-d352b(opens in new window)).
The COINFLIP project has made significant advances in fast optical transceivers through the exploration of various nanomaterials. Notably, CdSe and CuS nanocrystals, when combined with organic dyes, demonstrated expanded optical sensitivity, while Au nanoclusters revealed remarkable electric transport properties, leading to new avenues for micro-circuit fabrication. A key breakthrough was the achievement of ultra-fast response times—3 ps with WS2/graphene structures, surpassing state-of-the-art capabilities.
The project also developed new, scalable methods for integrating nanomaterials into devices, notably printing nanocrystal films onto micro-circuits for optical transceivers. These innovations offer immense potential for faster, energy-efficient communication networks, meeting the growing demand for high-speed data transmission. With nanomaterials like transition metal dichalcogenides, the project progressed from 2.6 MHz to 230 MHz in optical transceiver speed, paving the way for further technological advancements.
In addition, the project addressed fundamental limitations of materials like PbS nanocrystals, capping their speed at 1 nanosecond, and provided critical insights into combining nanocrystals and dyes. A significant societal impact of this research is the potential for optical interconnects with femtojoule power consumption, providing an energy-efficient solution to the limitations of modern electronics, which are nearing maximum power density. The project's innovations could revolutionize data centers and telecommunications systems, enabling faster, more efficient optical communication technologies.
In the future, we expect to refine material combinations further and improve response times, setting new standards for speed and efficiency in optical transceivers. These advancements promise long-term societal benefits by reducing energy consumption and enabling faster, more reliable global communication infrastructure.
The project also developed new, scalable methods for integrating nanomaterials into devices, notably printing nanocrystal films onto micro-circuits for optical transceivers. These innovations offer immense potential for faster, energy-efficient communication networks, meeting the growing demand for high-speed data transmission. With nanomaterials like transition metal dichalcogenides, the project progressed from 2.6 MHz to 230 MHz in optical transceiver speed, paving the way for further technological advancements.
In addition, the project addressed fundamental limitations of materials like PbS nanocrystals, capping their speed at 1 nanosecond, and provided critical insights into combining nanocrystals and dyes. A significant societal impact of this research is the potential for optical interconnects with femtojoule power consumption, providing an energy-efficient solution to the limitations of modern electronics, which are nearing maximum power density. The project's innovations could revolutionize data centers and telecommunications systems, enabling faster, more efficient optical communication technologies.
In the future, we expect to refine material combinations further and improve response times, setting new standards for speed and efficiency in optical transceivers. These advancements promise long-term societal benefits by reducing energy consumption and enabling faster, more reliable global communication infrastructure.