An overview of the medicinal plants of Turkey

Plant species have different uses in different countries as well as different areas of the same country (Farnsworth and Soejarto 1991; Plotkin 2000; Hamilton 2004; Halberstein 2005). The relationship between humans and plants has existed since the existence of human beings, and the earliest documented record dates from the Paleolithic age (50,000 BC); plants were found in the grave of a Neanderthal man in the southern part of Hakkari (far southeast edge of Turkey) (Baytop 1984, 1999). © 2012 by Taylor and Francis Group, LLC

Investigation of gate material ductility enables flexible a-IGZO TFTs bendable to a radius of 1.7 mm

TFTs on flexible plastic foils have the potential to enable new applications like electronic skins or smart textiles. Due to the temperature sensitivity of plastic substrates, amorphous In-Ga-Zn-O (a-IGZO) is a promising semiconductor since it provides a carrier mobility ≥10 cm2/Vs when deposited at room temperature. Therefore, a-IGZO TFTs have significantly increased electrical performance compared to organic TFTs, but also suffer from a decreased bendability. Here, focused ion beam (FIB) images are used to identify the gate metal as the dominant factor for the formation of cracks in bent a-IGZO TFTs. Flexible a-IGZO TFTs using a high-k Al2O 3 gate dielectric and different gate contact materials (Cr, Pt, Ti, or Cu) exhibit a similar effective mobility μFE, threshold voltage VTH, and on-off current ratio of: ≈15 cm2/Vs, ≈1 V, and ≥109. Simultaneously, bending experiments confirmed that their bendability depends on the ductility of the gate material. These findings are used to identify Cu as suitable gate material, and to fabricate a-IGZO TFTs on free-standing plastic foil which can be operated at a bending radius of 1.7 mm (1.55% strain), whereas bending shifts μFE and VTH only by + 2%, and - 6 mV. © 2013 IEEE