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- Matyba, Piotr, 1982-, et al.
(författare)
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Graphene and Mobile Ions: The Key to All-Plastic, Solution-Processed Light-Emitting Devices
- 2010
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Ingår i: ACS NANO. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 4:2, s. 637-642
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Tidskriftsartikel (refereegranskat)abstract
- The emerging field of "organic" or "plastic" electronics has brought low-voltage, ultrathin, and energy-efficient lighting and displays to market as organic light-emitting diode (OLED) televisions and displays in cameras and mobile phones. Despite using carbon-based materials as the light-emitting layer, previous efficient organic electronic light-emitting devices have required at least one metal electrode. Here, we utilize chemically derived graphene for the transparent cathode in an all-plastic sandwich-structure device, similar to an OLED, called a light-emitting electrochemical cell (LEC). Using a screen-printable conducting polymer as a partially transparent anode and a micro meter-thick active layer solution-deposited from a blend of a light-emitting polymer and a polymer electrolyte, we demonstrate a light-emitting device based solely on solution-processable carbon-based materials. Our results demonstrate that low-voltage, inexpensive, and efficient light-emitting devices can be made without using metals. In other words, electronics can truly be "organic".
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| 2. |
- Zhu, Yiru, et al.
(författare)
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Room-Temperature Photoluminescence Mediated by Sulfur Vacancies in 2D Molybdenum Disulfide
- 2023
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 17:14, s. 13545-13553
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Tidskriftsartikel (refereegranskat)abstract
- Atomic defects in monolayer transition metal dichalcogenides (TMDs) such as chalcogen vacancies significantly affect their properties. In this work, we provide a reproducible and facile strategy to rationally induce chalcogen vacancies in monolayer MoS2 by annealing at 600 °C in an argon/hydrogen (95%/5%) atmosphere. Synchrotron X-ray photoelectron spectroscopy shows that a Mo 3d5/2 core peak at 230.1 eV emerges in the annealed MoS2 associated with nonstoichiometric MoSx (0 < x < 2), and Raman spectroscopy shows an enhancement of the ∼380 cm-1 peak that is attributed to sulfur vacancies. At sulfur vacancy densities of ∼1.8 × 1014 cm-2, we observe a defect peak at ∼1.72 eV (referred to as LXD) at room temperature in the photoluminescence (PL) spectrum. The LXD peak is attributed to excitons trapped at defect-induced in-gap states and is typically observed only at low temperatures (≤77 K). Time-resolved PL measurements reveal that the lifetime of defect-mediated LXD emission is longer than that of band edge excitons, both at room and low temperatures (∼2.44 ns at 8 K). The LXD peak can be suppressed by annealing the defective MoS2 in sulfur vapor, which indicates that it is possible to passivate the vacancies. Our results provide insights into how excitonic and defect-mediated PL emissions in MoS2 are influenced by sulfur vacancies at room and low temperatures.
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