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- Xu, Guangwei, et al.
(författare)
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Synthesis, properties, and top-gated metal-oxide-semiconductor field-effect transistors of p-type GaSb nanowires
- 2013
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 3:43, s. 19834-19839
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Tidskriftsartikel (refereegranskat)abstract
- High-quality GaSb nanowires (NWs) have been synthesized via chemical vapor deposition. The as-synthesized NWs have a zinc-blende structure with growth direction along a < 011 > direction. Raman spectrum of the GaSb NWs consists of two peaks, corresponding to the LO and TO phonon modes, respectively. The temperature dependence of the photoluminescence spectra shows a blue-shift as the temperature decreases from 300 to 13 K. The electrical properties of the GaSb NWs are investigated over a wide range of temperatures from 25 mK to 291 K. The results show that the GaSb NWs exhibit excellent p-type transistor performance at low temperatures (<40 K). The room-temperature hole density and mobility were found to be similar to 2.2 x 10(18) cm(-3) and similar to 14.2 cm(2) V-1 s(-1), respectively. The Schottky contact characteristics were observed and the barrier height was found to be similar to 14 meV. Our results show that the GaSb NWs could be used as building blocks for emerging p-type nanoelectronic devices in extremely low temperature environments.
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| 2. |
- Zhou, Qiu-Jie, et al.
(författare)
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Out of chaos : Phylogenomics of Asian Sonerileae
- 2022
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier. - 1055-7903 .- 1095-9513. ; 175
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Tidskriftsartikel (refereegranskat)abstract
- Sonerileae is a diverse Melastomataceae lineage comprising ca. 1000 species in 44 genera, with >70% of genera and species distributed in Asia. Asian Sonerileae are taxonomically intractable with obscure generic circumscriptions. The backbone phylogeny of this group remains poorly resolved, possibly due to complexity caused by rapid species radiation in early and middle Miocene, which hampers further systematic study. Here, we used genome resequencing data to reconstruct the phylogeny of Asian Sonerileae. Three parallel datasets, viz. singlecopy ortholog (SCO), genomic SNPs, and whole plastome, were assembled from genome resequencing data of 205 species for this purpose. Based on these genome-scale data, we provided the first well resolved phylogeny of Asian Sonerileae, with 34 major clades identified and 74% of the interclade relationships consistently resolved by both SCO and genomic data. Meanwhile, widespread phylogenetic discordance was detected among SCO gene trees as well as species trees reconstructed using different tree estimation methods (concatenation/site-based coalescent method/summary method) or different datasets (SCO/genomic/plastome). We explored sources of discordance using multiple approaches and found that the observed discordance in Asian Sonerileae was mainly caused by a combination of biased distribution of missing data, random noise from uninformative genes, incomplete lineage sorting, and hybridization/introgression. Exploration of these sources can enable us to generate hypotheses for future testing, which is the first step towards understanding the evolution of Asian Sonerileae. We also detected high levels of homoplasy for some characters traditionally used in taxonomy, which explains current chaotic generic delimitations. The backbone phylogeny of Asian Sonerileae revealed in this study offers a solid basis for future taxonomic revision at the generic level.
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