ORCID Profile
0000-0002-4741-2358
Current Organisation
Karlsruher Institut für Technologie
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Publisher: Wiley
Date: 24-04-2019
Publisher: Springer Science and Business Media LLC
Date: 04-07-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7CP08452H
Abstract: Photoluminescence quantum yield enhancement based on energy transfer in surface-anchored metal–organic frameworks.
Publisher: The Optical Society
Date: 24-10-2017
DOI: 10.1364/OME.7.004082
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7CC08930A
Abstract: BODIPY–anthracene dyad shows two “faces” in triplet–triplet annihilation upconversion (TTA-UC) process: behaves either as a triplet sensitizer, or as a singlet emitter, depending on the media polarity.
Publisher: Springer Science and Business Media LLC
Date: 28-02-2019
DOI: 10.1038/S41467-019-08929-0
Abstract: Sustained stimulated emission under continuous-wave (CW) excitation is a prerequisite for new semiconductor materials being developed for laser gain media. Although hybrid organic-inorganic lead-halide perovskites have attracted much attention as optical gain media, the demonstration of room-temperature CW lasing has still not been realized. Here, we present a critical step towards this goal by demonstrating CW lified spontaneous emission (ASE) in a phase-stable perovskite at temperatures up to 120 K. The phase-stable perovskite maintains its room-temperature phase while undergoing cryogenic cooling and can potentially support CW lasing also at higher temperatures. We find the threshold level for CW ASE to be 387 W cm -2 at 80 K. These results indicate that easily-fabricated single-phase perovskite thin films can sustain CW stimulated emission, potential at higher temperatures as well, by further optimization of the material quality in order to extend the carrier lifetimes.
Publisher: Springer Science and Business Media LLC
Date: 03-05-2019
DOI: 10.1038/S41467-019-10011-8
Abstract: In molecular solids, the intense photoluminescence (PL) observed for solvated dye molecules is often suppressed by nonradiative decay processes introduced by excitonic coupling to adjacent chromophores. We have developed a strategy to avoid this undesirable PL quenching by optimizing the chromophore packing. We integrated the photoactive compounds into metal-organic frameworks (MOFs) and tuned the molecular alignment by introducing adjustable “steric control units” (SCUs). We determined the optimal alignment of core-substituted naphthalenediimides (cNDIs) to yield highly emissive J-aggregates by a computational analysis. Then, we created a large library of handle-equipped MOF chromophoric linkers and computationally screened for the best SCUs. A thorough photophysical characterization confirmed the formation of J-aggregates with bright green emission, with unprecedented photoluminescent quantum yields for crystalline NDI-based materials. This data demonstrates the viability of MOF-based crystal engineering approaches that can be universally applied to tailor the photophysical properties of organic semiconductor materials.
Publisher: Oxford University Press (OUP)
Date: 10-2019
Abstract: Salmonella species are major contributors to the global burden of foodborne disease. While typhoidal salmonella (TS) is typically associated with travel in high-income settings, non-typhoidal salmonella (NTS) is more commonly associated with locally acquired diarrhoeal disease. We aimed to assess the epidemiology, antimicrobial resistance (AMR) patterns, and clinical markers of Salmonella bloodstream infections (BSI) in Victoria, Australia. We conducted a retrospective audit of blood culture results over a 5.5-year period at a large, private pathology provider, in Victoria, Australia. All Salmonella isolates detected in blood between January 2013 and June 2018 were included. Epidemiological, microbiological, AMR and clinical data were extracted from the pathology record and collated for analysis. Of 27,546 positive blood cultures, 262 were positive for Salmonella spp. (rate 9.51 per 1,000 positive cultures) in 187 episodes. 113 (60%) were NTS (47.8% S. Typhimurium, 9.7% S. Enteritidis), while 74 (40%) were TS (59% S. Typhi, 41% S. Paratyphi). Patients with TS were younger (median age 29 vs. 65, P 0.0001), more likely to have traveled [OR 125 (95% CI 28.47, 549], but fewer had a positive stool [OR 0.21 (95% CI 0.08–0.58)] than those with NTS. NTS was associated with a higher median CRP (149 vs. 83, P 0.001) and more frequently associated with an abnormal white cell count (39% vs. 18%, P = 0.003). Quinolone non-susceptibility was stable with time, and occurred more frequently in TS than NTS (71 vs. 23%, P 0.0001). Non-susceptibility to Azithromycin was also common in TS (42%), and increasing with time (P = 0.02). Non-susceptibility to ≥1 antibiotic occurred in 54 (73%) of TS, while 24 (32%) had non-susceptibility ≥2. Ceftriaxone resistance occurred infrequently in both NTS and TS (2 vs. 0%, P = 0.5). Salmonella is an uncommon cause of BSI in our setting, with similar proportions of TS and NTS. Typhoidal isolates were more likely to be associated with travel, and antimicrobial resistance. Despite this, ceftriaxone remains a reliable option for first-line therapy for both TS and NTS. Quinolone resistance remains common, while Azithromycin resistance has increased with time in TS. All authors: No reported disclosures.
Publisher: Springer Science and Business Media LLC
Date: 18-10-2018
DOI: 10.1038/S41467-018-06829-3
Abstract: An ideal material for photon harvesting must allow control of the exciton diffusion length and directionality. This is necessary in order to guide excitons to a reaction center, where their energy can drive a desired process. To reach this goal both of the following are required short- and long-range structural order in the material and a detailed understanding of the excitonic transport. Here we present a strategy to realize crystalline chromophore assemblies with bespoke architecture. We demonstrate this approach by assembling anthracene dibenzoic acid chromophore into a highly anisotropic, crystalline structure using a layer-by-layer process. We observe two different types of photoexcited states one monomer-related, the other excimer-related. By incorporating energy-accepting chromophores in this crystalline assembly at different positions, we demonstrate the highly anisotropic motion of the excimer-related state along the [010] direction of the chromophore assembly. In contrast, this anisotropic effect is inefficient for the monomer-related excited state.
Publisher: American Physical Society (APS)
Date: 10-07-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9DT04497C
Abstract: Silicon nanocrystals with dyes covalently anchored to the crystal surface demonstrate improved visible light absorption and near-infrared luminescence enhancement – up to ∼270% and ∼140% under excitation with blue and green light, respectively.
Publisher: American Chemical Society (ACS)
Date: 31-01-2020
Abstract: Achieving efficient devices while maintaining a high fabrication yield is a key challenge in the fabrication of solution-processed, perovskite-based light-emitting diodes (PeLEDs). In this respect, pinholes in the solution-processed perovskite layers are a major obstacle. These are usually mitigated using organic electron-conducting planarization layers. However, these organic interlayers are unstable under applied bias in air and suffer from limited charge carrier mobility. In this work, we present a high brightness p-i-n PeLED based on a novel blade-coated silver microflake (SMF) rear electrode, which allows for a low-cost nanocrystalline ZnO inorganic electron-transporting layer to be used. This novel SMF contact is crucial for achieving high performance as it prevents the electrical shorting suffered when standard thermally evaporated silver rear contacts are used. The fabricated PeLEDs exhibit an excellent maximum luminance of 98,000 cd/m
Publisher: Elsevier BV
Date: 02-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9TA09584E
Abstract: This work studies spontaneous enhancement in power conversion efficiency of multi-cation-halide perovskite solar cells which occurs days after device fabrication.
No related grants have been discovered for Marius Jakoby.