Department of Applied Physics and Physico-Informatics, Keio University, Yokohama, 223-8522, Japan.
Published: March 2018
AI Article Synopsis
Article Abstract
High-speed light emitters integrated on silicon chips can enable novel architectures for silicon-based optoelectronics, such as on-chip optical interconnects, and silicon photonics. However, conventional light sources based on compound semiconductors face major challenges for their integration with a silicon-based platform because of their difficulty of direct growth on a silicon substrate. Here we report ultra-high-speed (100-ps response time), highly integrated graphene-based on-silicon-chip blackbody emitters in the near-infrared region including telecommunication wavelength. Their emission responses are strongly affected by the graphene contact with the substrate depending on the number of graphene layers. The ultra-high-speed emission can be understood by remote quantum thermal transport via surface polar phonons of the substrates. We demonstrated real-time optical communications, integrated two-dimensional array emitters, capped emitters operable in air, and the direct coupling of optical fibers to the emitters. These emitters can open new routes to on-Si-chip, small footprint, and high-speed emitters for highly integrated optoelectronics and silicon photonics.
China's energy mix is coal-dominated; therefore, it is unrealistic for the country to achieve carbon neutrality through complete decarbonization. As the world's largest carbon emitter, achieving global carbon reduction targets necessitates that China develops low-carbon, clean, safe, and efficient coal development and utilization technologies. This study proposes a new low-carbon coal development and utilization method that integrates in-situ conversion mining and mineral carbonation (ICMMC) to realize coal mining and separation, in-situ backfilling, in-situ conversion, energy storage, and carbon sequestration.
Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
Narrowband fluorescent emitters are receiving significant attention due to the great potential for creating ultrahigh-definition organic light-emitting diode displays (UHD-OLED). Unveiling innovative mechanisms to design new high-performance narrowband fluorescent emitters is a concerted endeavor in both academic and industrial circles. Theoretical calculations reveal that the centrosymmetric dianilido-bipyridine boron difluoride framework (-DAPBF) exhibits significantly reduced structural relaxation compared to previously reported asymmetric structures with monofluoroboron cores, creating new opportunities for the development of narrowband fluorescent emitters.
Near-infrared (NIR) emitters with high two-photon absorption (2PA) cross-sections are of interest to enable imaging in the tissue transparency windows. This study explores the potential of DNA-stabilized silver nanoclusters (Ag -DNAs) as water-soluble two-photon absorbers. We investigate 2PA of four different atomically precise Ag -DNA species with far-red to NIR emission and varying nanocluster and ligand compositions.
To experimentally investigate the impact of macrocyclic structures on the nonradiative decay rate constants () of thermally activated delayed fluorescence (TADF), a macrocyclic molecule L-ring and its analogue NL-ring were designed and synthesized. The photophysical measurements reveal their TADF characteristics, and the of the L-ring (4.19 × 10 s) is slower than that of the NL-ring (1.
Fluorescence emission regulation is of great interest for its promising applications in various fields such as microscopy, chemical analysis, encryption, and sensing. Most studies focus on the regulation of the fluorescence emission process. However, the spectral separation of excitation and emission of fluorophores requires careful design of resonances to cover both emission and excitation wavelengths, which is a better choice to enhance fluorescence intensity.
