Tomas Syrovy

Preparation of arsenic sulfide thin films for integrated optical elements by spiral bar coating

We report on the preparation of thin As35S65 films from their amine based solutions by a spiral bar coating technique on flexible PET substrates and the direct writing of subwavelength surface corrugated gratings with a period of 350 nm into these films by excimer laser interference lithography. The structural and optical properties of bar coated As35S65 glass are investigated in detail and compared with those of samples fabricated by vacuum thermal evaporation. The polarization dependent spectral filtering properties of the guided mode resonance devices built by the waveguiding thin films and the surface relief gratings written by a single laser pulse are presented finally.

Determination of Zinc, Cadmium, Lead, Copper and Silver Using a Carbon Paste Electrode and a Screen Printed Electrode Modified with Chromium(III) Oxide

In this study, the preparation and electrochemical application of a chromium(III) oxide modified carbon paste electrode (Cr-CPE) and a screen printed electrode (SPE), made from the same material and optimized for the simple, cheap and sensitive simultaneous determination of zinc, cadmium, lead, copper and the detection of silver ions, is described. The limits of detection and quantification were 25 and 80 µg·L−1 for Zn(II), 3 and 10 µg·L−1 for Cd(II), 3 and 10 µg·L−1 for Pb(II), 3 and 10 µg·L−1 for Cu(II), and 3 and 10 µg·L−1 for Ag(I), respectively. Furthermore, this promising modification was transferred to the screen-printed electrode. The limits of detection for the simultaneous determination of zinc, cadmium, copper and lead on the screen printed electrodes were found to be 350 µg·L−1 for Zn(II), 25 µg·L−1 for Cd(II), 3 µg·L−1 for Pb(II) and 3 µg·L−1 for Cu(II). Practical usability for the simultaneous detection of these heavy metal ions by the Cr-CPE was also demonstrated in the analyses of wastewaters.

Ionic liquid as an electrolyte for organic electrochemical transistor

The presented study is focused on the improvements of static and dynamic characteristics of organic electrochemical transistor (OECT). Especially the switching speed, the switching ratio and stability were examined. For the given study a special structure of the OECT has been developed for the evaluation of various materials and their influence on selected characteristics. Conductive polymer poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) was used as the main material for channel of OECT device. The influence of two ionic liquids (ILs) used as an electrolyte in OECT is compared. The results indicate a significant difference between ILs and their suitability to be used as electrolyte in the OECT.

Organic electrochemical transistor based on ionic liquid: The temperature effect

The paper is focused on the study of electric and temperature properties of electrochemical transistor based on ionic liquid, 1-ethyl-3-methylimidazolium ethyl sulfate. The transistor shows good output source-drain character- istics. The switching characteristics are as follows: The current switching is from –1.1×10−4 A to –1.5 ×10−7A, i.e., the switching ratio is about 700. The current kinetics can be described by stretched exponential function. The current-temperature dependence follows well the Arrhenius equation. Activation energy of the source-drain current is 0.1 eV in the closed state and 0.02 eV in the open state. Both activation energies are voltage independent.The paper is focused on the study of electric and temperature properties of electrochemical transistor based on ionic liquid, 1-ethyl-3-methylimidazolium ethyl sulfate. The transistor shows good output source-drain character- istics. The switching characteristics are as follows: The current switching is from –1.1×10−4 A to –1.5 ×10−7A, i.e., the switching ratio is about 700. The current kinetics can be described by stretched exponential function. The current-temperature dependence follows well the Arrhenius equation. Activation energy of the source-drain current is 0.1 eV in the closed state and 0.02 eV in the open state. Both activation energies are voltage independent.

Influence of aging on printed passive components parameters

This paper deals with the design of passive components created on flexible substrates by the screen printing technology and the aging influence on their electrical parameters. The screen printing technology is current used for printed passive components such as resistors, inductors, capacitors. Now there are many types of patterns for these passive components and many screen printing pastes on the market. The problem can be with long term stability of electrical parameters of these printed passive components. The aim of this paper was to determine influence of aging on electrical parameters of screen printed passive components. There is also included a comparison between calculated and measured values of particular passive components.

Comparison of quasi-solid state and liquid electrolytes for organic electrochemical transistor

The study is focused on a comparison of quasi-solid and liquid electrolytes for organic electrochemical transistor (OECT). Especially influences of used electrolytes on the switching speed and the switching ratio were compared. For the given study a three electrode structure of the OECT has been used for the evaluation of various materials and their influence on selected characteristics. For the channel of the OECT device, conductive polymer poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT.PSS) was used. Two different ionic liquids and one quasi-solid state electrolyte were used and compared in OECT structure. The results show that both OECTs with ionic liquids are faster than the OECT with quasi-solid state electrolyte but have approximately 10 times smaller switching ratio.

Printed inductors for RFID tags

The article describes various options of receiving printing inductors for passive RFID tags which work at frequency 13.56 MHz. Different variants of producing inductors using the technology of screen printing with different materials of the conductive paste and the number of layers deposited by a variety of substrate materials were investigated. Assessments of the impact of the factors stated above on electrical parameters of the researched samples were made. After the analysis of measurement data of inductance, quality factor, resonant frequency and impedance the authors offered the option of manufacturing printed inductors for RFID tags.