Mechanical bending of flexible complementary inverters based on organic and oxide thin film transistors

The effect of the channel width dimension on the electrical characteristics of amorphous/nanocrystalline silicon bilayer thin-film transistors (TFTs) is investigated. For comparison, nanocrystalline silicon monolayer TFTs are also studied. The experimental results show that the leakage current is decreased and the back-channel conduction is suppressed in bilayer channel devices. The overall results demonstrate that the performance of bilayer TFTs is enhanced with decreasing the channel width, which is attributed to the corner effect

Effect of Channel Width on the Electrical Characteristics of Amorphous/Nanocrystalline Silicon Bilayer Thin-Film Transistors

The present chapter is devoted to the synthesis and applications of nanodiamond. Nanodiamond or nanocrystalline diamond is actually an allotrope of carbon which has nanosized carbon crystallites having well-known diamond structure. Although it is present in nature since long, the realization of its artificial production occurred in the 1960s by the Russian scientists. Due to the policy of secret research, it was in dark until 1980s, when the first formal report of its synthesis was published. Since then, it has been remained in the focus of scientists and researchers worldwide. Several techniques for the synthesis of nanodiamond have been developed. This chapter presents all the major techniques used for the synthesis of nanodiamond particles as well as thin films. Due to its excellent mechanical and optical properties, high surface area, non-toxicity and tenability of its surface structure, nanodiamond has been widely used in various applications. This chapter reviews some interesting applications of nanodiamond, especially, the recent ones.

Nanomaterials and Their Applications

Dielectric properties of thin films precipitated on solid substrates from colloidal solutions containing silicon nanoparticles (average diameter is 10 nm) are studied by optical ellipsometry and impedance-spectroscopy. In the optical region, the values of real ɛ′ and imaginary ɛ″ components of the complex permittivity ɛ vary within 2.1–1.1 and 0.25–0.75, respectively. These values are significantly lower than those of crystalline silicon. Using numerical simulation within the Bruggeman effective medium approximation, we show that the experimental ɛ′ and ɛ″ spectra can be explained with good accuracy, assuming that the silicon film is a porous medium consisting of silicon monoxide (SiO) and air voids at a void ratio of 0.5. Such behavior of films is mainly caused by the effect of outer shells of silicon nanoparticles interacting with atmospheric oxygen on their dielectric properties. In the frequency range of 10–106 Hz, the experimentally measured ɛ′ and ɛ″ spectra of thin nanoscale silicon films are well approximated by the semi-empirical Cole-Cole dielectric dispersion law with the term related to free electric charges. The experimentally determined power-law frequency dependence of the ac conductivity means that the electrical transport in films is controlled by electric charge hopping through localized states in the unordered medium of outer shells of silicon nanoparticles composing films. It is found that the film conductivity at frequencies of ≤2 × 102 Hz is controlled by proton transport through Si-OH groups on the silicon nanoparticle surface.

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Dielectric and transport properties of thin films precipitated from sols with silicon nanoparticles

v Introduction 1 I Scattering for the stationary Schrodinger equation on the plane 7 1 Direct scattering for the two-dimensional Schrodinger equation at E 6= 0 . . . . 7 1.1 Classical scattering functions, scattering amplitude and Faddeev exponentially growing solutions . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.2 Faddeev scattering data and their properties . . . . . . . . . . . . . . . . 13 2 Direct scattering for the two-dimensional Schrodinger equation at E = 0 . . . . 17 II Existence/absence of solitons for the Novikov-Veselov equation 20 3 Soliton solutions of the Novikov-Veselov equation . . . . . . . . . . . . . . . . . 20 3.1 Grinevich-Zakharov solutions . . . . . . . . . . . . . . . . . . . . . . . . 20 3.2 Dynamical properties of Grinevich-Zakharov solutions (proofs of Lemmas 3.1, 3.2 and Theorem 3.1) . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4 Absence of sufficiently localized solitons at E 6= 0 . . . . . . . . . . . . . . . . . 29 4.1 Formulation and proof of the result . . . . . . . . . . . . . . . . . . . . . 30 4.2 Vanishing scattering data for the localized soliton solutions of the NovikovVeselov equation at E 6= 0 (proof of Lemma 4.4) . . . . . . . . . . . . . . 32 4.3 Dynamics of scattering data (proofs of Lemmas 4.1, 4.2) . . . . . . . . . 36 5 Absence of conductivity type solitons at E = 0 . . . . . . . . . . . . . . . . . . . 42 iii pa st el -0 07 62 66 2, v er si on 1 7 D ec 2 01 2

http://math.as.uky.edu/sites/default/files/Kazeykina%20Thesis-2012.pdf

Docteur de l'école polytechnique

Thin-film transistors were made using 50-nm-thick directly deposited nanocrystalline silicon channel layers. The transistors have a coplanar top gate structure. The nanocrystalline silicon was deposited from discharges in silane, hydrogen and silicon tetrafluoride. The transistors combine a high electron field effect mobility of ∼10 cm2 V-1s-1 with a low ‘off’ current of ∼10-14 A per μm of channel length and an ‘on’/‘off’ current ratio of ∼108. This result shows that transistors made from directly deposited silicon can combine high mobility with low ‘off’ currents.

R.B. Min

Papers

Nanocrystalline silicon thin-film transistors with 50-nm-thick deposited channel layer, 10 cm2v-1s-1 electron mobility and 108 on/off current ratio