Search

This study investigates InSnZnO thin films deposited using mist chemical vapor deposition with different nitrogen (N 2)/oxygen (O 2) ratios of carrier gases. The crystallinity and bandgap of InSnZnO are not affected by the carrier gases; however, the content of the oxygen deficiency of the InSnZnO thin films reduces when the N 2 /O 2 mixed carrier gases have higher oxygen ratio. The InSnZnO thin-film transistor (TFT) shows the highest field-effect mobility (65.04 cm2V−1s−1) when N 2 is used as the carrier gas to deposit the InSnZnO thin film. Although the field-effect mobility of the InSnZnO TFT that uses the N 2 (60 vol%)/O 2 (40 vol%) mixed carrier gas to deposit InSnZnO thin film is the lowest (47.65 cm2V−1s−1), it is still higher than those of the amorphous InGaZnO thin film transistors (∼10 cm2V−1s−1). Furthermore, the InSnZnO TFT using the N 2 (60 vol%)/O 2 (40 vol%) mixed carrier gas to deposit InSnZnO thin film exhibits the steepest subthreshold slope (102 mV/dec), the largest on/off current ratio (4.6 × 107), and the most stable electrical characteristics after the negative bias stress test for 10,800 s. [ABSTRACT FROM AUTHOR]

[Display omitted] • 169 accessions representing ca. 68 (85% of total) species of Bolbitis are sampled. • Species of Bolbitis are resolved into four major clades. • Six well-supported subclades are identified in the most speciose Asian clade. • Evolution of six characters is analyzed and free venation evolved from anastomosing venation in Bolbitis. • Bolbitis originated from Africa and a dispersal from Asia resulted in continental disjunction between Africa and America. Bolbitis is a pantropical fern genus of Dryopteridaceae with ca. 80 species mainly in tropical Asia. Earlier studies confirmed the monophyly of Bolbitis when Mickelia is excluded and identified three major clades in Bolbitis. However, earlier studies are based on relatively small sampling and the majority of Asian species are not sampled. In this study, DNA sequences of three plastid markers of 169 accessions representing ca. 68 (85 % of total) species of Bolbitis in nine out of the 10 series recognized by Hennipman (1977), and 54 accessions representing the five remaining bolbitidoid genera are used to infer a global phylogeny with a focus on Asian species. The major results include: (1) Bolbitis is strongly supported as monophyletic; (2) species of Bolbitis are resolved into four major clades and their relationships are: the Malagasy/Mascarene clade is sister to the rest, followed by the African clade which is sister to the American clade + the Asian clade; (3) six well-supported subclades are identified in the most speciose Asian clade; (4) the free-veined Egenolfia is embedded in Bolbitis and is paraphyletic in relation to species with anastomosing venation; (5) three series sensu Hennipman (1977), B. ser. Alienae , B. ser. Egenolfianae , and B. ser. Heteroclitae , are paraphyletic or polyphyletic; (6) evolution of six morphological characters is analyzed and free venation is found to have evolved from anastomosing venation and reversed to free venation in Bolbitis ; and (7) biogeographical implications are drawn and it is shown that a single recent dispersal from Asia resulted in continental disjunction of closely related ferns of Bolbitis between Africa and America. [ABSTRACT FROM AUTHOR]