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- Luo, Xuhao, et al.
(author)
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Intrinsic polarization-sensitive organic photodetector with self-assembled all-polymer heterojunction
- 2022
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 121:23
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Journal article (peer-reviewed)abstract
- Intrinsic polarization-sensitive photodetectors (IPPDs) have attracted considerable attention in recent years due to their simplicity in configuration, making them ideal candidates for compact and integrated polarization-sensitive sensing and imaging systems. Photoactive films with intrinsic optical anisotropy are necessary for IPPDs. This study reports an achievement of photoactive films based on all-polymer heterojunction films with in-plane optical anisotropy using a simple bottom-up self-assembly method. Both the donor (TQ1) and acceptor (N2200) polymers have the same spatial orientation with distinct anisotropy, approaching a dichroic ratio (DR) of 8. Polarization-sensitive light absorption is due to the uniaxially oriented polymer chains, which are dominated by lamellar packing with edge-on orientation. For IPPDs based on this anisotropic all-polymer heterojunction film, a photocurrent anisotropy was found with a polarized photocurrent ratio of 2.6. The detectivity of these IPPDs was found to be 1.9 × 1011 Jones (@ ∼600 nm, 0 V bias). Our work shows that oriented polymer donor-acceptor films fabricated using bottom-up self-assembly have great potential in applications, such as polarization detection.
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2. |
- Xue, Tian-Tian, et al.
(author)
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Ignored Biodiversity in Acid Soil Islands in Karst Areas, South China : Impatiens longlinensis (Balsaminaceae), a New Critically Endangered Species
- 2020
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In: Systematic Botany. - 0363-6445 .- 1548-2324. ; 45:4, s. 891-899
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Journal article (peer-reviewed)abstract
- The karst area in South China is notable for its fragile vegetation and unique flora with many narrow endemic species, and is one of the most threatened biodiversity hotspots in the world. However, the biodiversity of acid soil areas scattered in the karst area have previously been underestimated. With a recent increase of new discoveries of plants and animals, the conservation of biodiversity in these acid soil areas has become urgent. This study deals with a new species, Impatiens longlinensis . The new species is similar to I. yui and I. lasiophyton in having pubescence, two lateral sepals, funnelform lower sepal, and linear capsule. But it can be distinguished by having orbicular to obovate dorsal sepals and oblong to elliptic lower and upper lobes of lateral united petals. Moreover, molecular data and micro-morphological evidence also support that the species is new to science. The new species is only known from a valley near the summit of Mt. Jinzhongshan within an area of less than 5 km2. Based on the Red List categories and criteria developed by the International Union for Conservation of Nature, and the threat posed by exploitation for tourism development, we categorize it as Critically Endangered (CR).
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