0000000000164043
AUTHOR
Zanda Gertnere
Optical properties of ultrathin Al2O3/ZnO nanolaminates
Abstract Because of their high resistance against ultraviolet and high energy particles, ultrathin amorphous nanolaminates can be very attractive for aerospace application. Here we report on the optical and structural properties of ultrathin Al2O3/ZnO nanolaminates deposited by Atomic Layer Deposition. Structural properties of nanolaminates were studied by GIXRD and AFM. Optical characterization was performed by transmittance, spectroscopic ellipsometry and photoluminescence (PL) spectroscopy. Regression analysis of ellipsometric spectra has shown that absorption peak decreases and blue shifted with the decrease of bilayer thickness in the stack. On the basis of the analysis of structural a…
Tuning Optical Properties of Al 2 O 3 /ZnO Nanolaminates Synthesized by Atomic Layer Deposition
Nanolaminates are of great interest for their unique properties such as high dielectric constants and advanced mechanical, electrical, and optical properties. Here we report on the tuning of optical and structural properties of Al2O3/ZnO nanolaminates designed by atomic layer deposition (ALD). Structural properties of nanolaminates were studied by SEM, GIXRD, and AFM. Optical characterization was performed by transmittance and photoluminescence (PL) spectroscopy. Complex study of monolayer properties was performed by ellipsometry. Optical constants for Al2O3 and ZnO monolayer were calculated. The band gap of ZnO single layers and the excitonic PL peak position were shifted to the UV region …
Optical field-induced surface-relief micropatterning of amorphous chalcogenide thin films
The study of direct recording of the surface relief gratings on amorphous chalcogenide thin (2.5 to 5 μm films is presented by three different recording setups. Recording was performed on As2S3 by 532-nm wavelength laser light. Additionally, the evolution of a surface relief in dependence from the recording time and polarization has been investigated in detail and for the first time, the mass transfer process has been explained from the point of view of the photoinduced birefringence. The role of photoinduced plasticity in the formation of surface relief in amorphous chalcogenides during holographic recording has been discussed.
Application of Room Temperature Photoluminescence From ZnO Nanorods for Salmonella Detection
ZnO nanorods grown by gaseous-disperse synthesis are confirmed by XRD analysis to have the wurtzite crystal structure. The obtained crystallites, as found from SEM studies, are 57 +/- 9 nm in diameter and 470 +/- 30 nm long on the average. Two emission bands of photoluminescence from ZnO nanorods observed at room temperature are centered at 376 and 520 nm. A biosensitive layer is prepared by immobilization of anti-Salmonella antibodies from liquid solutions on the ZnO surface. Immobilization of the biosensitive layer onto ZnO nanorods is found to increase the intensity of PL. After further reaction with Salmonella antigens (Ags), the PL intensity is found to decrease proportional to Ag conc…
The influence of localized plasmons on the optical properties of Au/ZnO nanostructures
Optical and structural experiments have been carried out on Si/ZnO thin films modified with ultra-thin gold layers of different thicknesses. ZnO was produced via Atomic Layer Deposition (ALD) and Au via Physical Vapor Deposition (sputtering). The structural properties of nanostructures were studied by XRD and AFM. Optical characterization was performed by absorbance, photoluminescence (PL) and spectroscopic ellipsometry (SE). A transition from cluster-to-thin films with the increase of Au thickness has been revealed from an analysis of optical and structural parameters. The analysis of optical features of the system has shown that slight changes of the localized plasmon absorption peaks in …
Application of electrochemical impedance for characterising arrays of Bi2S3 nanowires
Abstract Electrochemical Impedance Spectroscopy (EIS) was used to characterise the electrical properties of bismuth sulphide (Bi2S3) nanowires (NWs) templated within anodic aluminium oxide (AAO) membranes. A specially engineered cell, with a nominal electrolyte volume of 0.1–0.2 ml, was used to hold and measure the electrochemical impedance of the fragile NW/AAO samples. An equivalent circuit model was developed to determine the filling density of nanowires within the porous templates. The EIS method can be utilised to probe the nanowire filling density in porous membranes over large sample areas, which is often unobtainable using electron microscopy and conductive atomic force microscopy t…
Optical-field induced volume- and surface-relief formation phenomenon in thin films of vitreous chalcogenide semiconductors
In this report the study of direct recording of the surface relief gratings on amorphous chalcogenide thin (2.5-5μm) films is presented by three different recording setups. Recording was performed on As2S3 by 532nm wavelength laser light. Additionally the evolution of surface relief in dependence from the recording time and polarization has been investigated in detail. The mechanism of the direct recording of surface relief on amorphous chalcogenide films based on the photo-induced plasticity has been discussed.