| 1. |
- Sun, Bianjing, et al.
(author)
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Sustainable Amylopectin-Derived Miniwindmills for Moisture-Induced Electric Generation
- 2022
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In: Advanced Energy and Sustainability Research. - : Wiley. - 2699-9412. ; 3:11
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Journal article (peer-reviewed)abstract
- Capturing energy from the environment provides the hope for clean energy and enables the formation of self-powered systems. Nanostructured functional materials can interact with water to generate electrical energy, greatly expanding the technical capabilities of water energy harvesting, while those derived from sustainable biomass for this purpose are still in the infancy. Herein, a series of thin self-standing amylopectin-derived membranes of several micrometers can output hydrovoltaic electric energy in the ambient environment. One single-unit flat device (around 0.78 cm2) can generate an instant voltage of up to 0.95 V from high ambient humidity. The underlying mechanism for generating electricity from amylopectin-derived membranes is attributed to the fast adsorption and desorption of water molecules on the membrane surface based on the results of dynamic vapor sorption. Novel moisture-induced miniwindmills as electric generators are fabricated, thanks to these outstanding features such as being self-standing, flexible, lightweight, and having ease of scale production. Such miniwindmill devices with a membrane layer thickness of ≈10 μm can be used to harvest energy with a sustained voltage of around 0.45 V from ambient environment. These results pave the way for developing energy-harvesting powerful minisized devices that exploit water gradients prevalent in nature with biomass materials.
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| 2. |
- Wu, Zhongbin, et al.
(author)
-
Achieving Extreme Utilization of Excitons by an Efficient Sandwich-Type Emissive Layer Architecture for Reduced Efficiency Roll-Off and Improved Operational Stability in Organic Light-Emitting Diodes
- 2016
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In: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 8:5, s. 3150-3159
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Journal article (peer-reviewed)abstract
- It has been demonstrated that the efficiency roll-off is generally caused by the accumulation of excitons or charge carriers, which is intimately related to the emissive layer (EML) architecture in organic light-emitting diodes (OLEDs). In this article, an efficient sandwich-type EML structure with a mixed-host EML sandwiched between two single-host EMLs was designed to eliminate this accumulation, thus simultaneously achieving high efficiency, low efficiency roll-off and good operational stability in the resulting OLEDs. The devices show excellent electroluminescence performances, realizing a maximum external quantum efficiency (EQE) of 24.6% with a maximum power efficiency of 105.6 lm W-1 and a maximum current efficiency of 93.5 cd A(-1). At the high brightness of 5 000 cd m(-2), they still remain as high as 23.3%, 71.1 lm W-1, and 88.3 cd A(-1), respectively. And, the device'lifetime is up to 2000 h at initial luminance of 1000 cd m(-2), which is significantly higher than that of compared devices with conventional EML structures. The improvement mechanism is systematically studied by the dependence of the exciton distribution in EML and the exciton quenching processes. It can be seen that the utilization of the efficient sandwich-type EML broadens the recombination zone width, thus greatly reducing the exciton quenching and increasing the probability of the exciton recombination. It is believed that the design concept, provides a new avenue for us to achieve high-performance OLEDs.
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