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In this paper, the ferroelectric (FE) properties of 20-nm-thick Hf0.5Zr0.5O2 films deposited by an atomic layer deposition technique by using O3 or H2O as an oxygen source were studied. For both oxygen source, the Hf0.5Zr0.5O2 films exhibited the formation of a non-centrosymmetric orthorhombic phase, which was responsible for the FE behavior. However, it was shown that the H2O-based Hf0.5Zr0.5O2 films were more unsuitable for hydrogen from H2O than the O3-based Hf0.5Zr0.5O2 films, which reduced the FE polarization and increased the leakage behavior. The results indicated that the use of O3 as an oxygen source in the ALD process has potential for the fabrication of FE Hf0.5Zr0.5O2 films for next generation memory applications. [ABSTRACT FROM AUTHOR]

Reducing geometry size of lithium niobate (LN)-based photonic elements is imperative for realizing ultra-compact LN photonic systems with novel functionalities. However, precision fabrication of LN structures of tens-of-nanometers and below is a challenging task. Focused ion beam (FIB) is promising for ultra-smooth LN nano-patterning due to its flexibility and high resolution. However, tremendous surface roughness was left on the LN surface during FIB milling because of the inhomogenous etching of the metallic film, coated on LN surface to avoid charge accumulation. To achieve ultra-smooth patterns, in this paper, an organic conductive resist was used as an alternative to metallic films. The results showed that surface roughness was kept lower than 0.6 nm with etching depth from hundreds of nanometers to several nanometers. Ultra-shallow steps were fabricated on LN surface with controllable 10 nm step height. This work paves the way to the ultra-smooth and ultra-shallow FIB patterning of LN nano-structures. [ABSTRACT FROM AUTHOR]

A voltage-pulse method is utilized to investigate the charge-injection-induced time decay of the source–drain current of field-effect transistors with randomly networked single-walled carbon nanotubes (CNTs) as the conduction channel. The relaxation of trapped carriers in the CNT networks can be accounted for by assuming two exponential decays occurring simultaneously. The slow decay is characterized by a time constant comparable to literature data obtained for a carrier recombination in the semiconducting CNTs. The faster decay with a time constant that has a smaller order of magnitude is attributed to the annihilation of trapped carriers in metallic CNTs or at metal-CNT contacts. Both time constants are gate-bias dependent. [ABSTRACT FROM PUBLISHER]

It is shown in this letter that the field-effect electrical response of transistors with their channel made of networks of single-walled carbon nanotubes (SWNTs) embedded in a poly(3-hexylthiophene) (P3HT) matrix can be significantly altered by light illumination. The experimental results indicate a photo-activated electron transfer from P3HT selectively to the semiconducting SWNTs. This finding points to a potential optoelectronic application of such a field-effect device as a photo-triggered electronic switch. [ABSTRACT FROM AUTHOR]

Hysteresis in the current-voltage characteristics is one of the major obstacles to the implementation of organic thin-film transistors in large-area integrated circuits. The hysteresis has been correlated either extrinsically to various charge-trapping/transfer mechanisms arising from gate dielectrics or surrounding ambience or intrinsically to the polaron-bipolaron reaction in low-mobility conjugated polymer thin-film transistors. However, a comprehensive understanding essential for developing viable solutions to eliminate hysteresis is yet to be established. By embedding carbon nanotubes in the polymer-based conduction channel of various lengths, here we show that the bipolaron formation/recombination combined with the H2O/O2 electrochemical reaction is responsible for the hysteresis in organic thin-film transistors. The bipolaron-induced hysteresis is a thermally activated process with an apparent activation energy of 0.29 eV for the bipolaron dissociation. This finding leads to a hysteresis model that is generally valid for thin-film transistors with both band transport and hopping conduction in semiconducting thin films.