Synthesis, Characterization, Defect Chemistry, and FET Properties of Microwave-Derived Nanoscaled Zinc Oxide

Abstract

The formation of nanoscale zinc oxide particles with an almost-monomodal size distribution synthesized by microwave heating of solutions of mononuclear zinc oximato or zinc acetylacetonato complexes in various alkoxyethanols is investigated. Transparent stable suspensions that contain these particles can be obtained from the zinc oximato precursor. Based on electron paramagnetic resonance (EPR) studies, a core/shell model with a finite surface shell thickness of 1.000 ± 0.025 nm is proposed for the ZnO nanoparticles. Field-effect transistor (FET) devices with these ZnO particles as the active semiconducting layer exhibited a charge carrier mobility of 0.045 cm2/(V s) and I on/off current ratios of ∼460.000, with a threshold voltage of 8.78 V.

Raman scattering and photoluminescence studies of ZnO nanowhiskers assembled as flowers in the presence of fullerene

“…1a is the variation in the intensity of the PL spectra of the ZnO nanoparticles of whisker-type between the case when the measurements were made successively at room temperature (RT) in air and the case where measurements were made under a vacuum of approximately 5.4 10 -5 mbar. The decrease in the PL intensity in vacuum is due to the removal of physically adsorbed entities on the surface of the particles, i.e., oxygen or OH groups [26], which reduced the number of trapping centers of electrons and holes. Such behavior was not observed for the ZnO/C 60 composite.…”

Effect of surface-to-volume ratio on the optical and magnetic properties of ZnO nanorods by hydrothermal method

“…The data showed the major characteristic ZneO vibration at 542 cm À1 and 506 cm À1 [13e15]. The broad absorption band at~3440 cm À1 , which is commonly observed in ZnO nanostructures prepared by hydrothermal method at low temperature, can be attributed to the hydroxyl groups [16]. The weak absorption bands at 1385 and 880 cm À1 are associated with valence vibration of carboxylate groups C]O and the optical mode due to electronic transition in ZnO [17], respectively.…”

Modulation of the electron transfer processes in Au–ZnO nanostructures

“…In fact, different EPR signals with g-factors near 2.01, 1.96 and 1.97, have previously been detected and assigned to oxygen vacancies, Zn interstitials, and hydrogen interstitials, respectively. [47][48][49] However, a different behaviour was found for the synthesized Au/ZnO nanostructures in the dark, which showed a small feature at g = 1.9655, as shown in curve (b) of Fig. 7.…”