scholarly journals Imaging of Chemical Reactions Using a Terahertz Chemical Microscope

Photonics ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 10 ◽  
Author(s):  
Toshihiko Kiwa ◽  
Tatsuki Kamiya ◽  
Taiga Morimoto ◽  
Kentaro Fujiwara ◽  
Yuki Maeno ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Reactions ◽  
Field Effect ◽  
Film Surface ◽  
Experimental Setup ◽  
Substrate Side ◽  
Surface Field ◽  
Silicon Based ◽  
Si Thin Film

This study develops a terahertz (THz) chemical microscope (TCM) that visualizes the distribution of chemical reaction on a silicon-based sensing chip. This chip, called the sensing plate, was fabricated by depositing Si thin films on a sapphire substrate and thermally oxidizing the Si film surface. The Si thin film of the sensing plate was irradiated from the substrate side by a femtosecond laser, generating THz pulses that were radiated into free space through the surface field effect of the Si thin film. The surface field responds to chemical reactions on the surface of the sensing plate, changing the amplitude of the THz pulses. This paper first demonstrates the principle and experimental setup of the TCM and performs the imaging and measurement of chemical reactions, including the reactions of bio-related materials.

Exotic Doping for Zno Thin Films: Possibility of Monolithic Optical Integrated Circuit

1999 ◽  
Vol 574 ◽  
Author(s):  
Norifumi Fujimura ◽  
Tamaki Shimura ◽  
Toshifumi Wakano ◽  
Atsushi Ashida ◽  
Taichiro Ito
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Nonlinear Optic ◽  
Integrated Circuit ◽  
Film Surface ◽  
Zno Thin Films ◽  
Process Window ◽  
Electro Optic ◽  
Film Substrate ◽  
Optical Integrated Circuit

AbstractWe propose the application of ZnO:X (X = Li, Mg, N, In, Al, Mn, Gd, Yb etc.) films for a monolithic Optical Integrated Circuit (OIC). Since ZnO exhibits excellent piezoelectric effect and has also electro-optic and nonlinear optic effects and the thin films are easily obtained, it has been studied as one of the important thin film wave guide materials especially for an acoustooptic device[1]. In terms of electro-optic and nonlinear optic effects, however, LiNbO3 or LiTaO3 is superior to ZnO. The most important issue of thin film waveguide using such ferroelectrics is optical losses at the film/substrate interface and the film surface, because the process window to control the surface morphology is very narrow due to their high deposition temperature. Since ZnO can be grown at extremely low temperature, the roughness at the surface and the interface is expected to be minimized. This is the absolute requirement especially for waveguide using a blue or ultraviolet laser. Recently, lasing at the wavelength of ultraviolet, ferroelectric and antiferromagnetic behaviors of ZnO doped with various exotic elements (exotic doping) have been reported. This paper discusses the OIC application of ZnO thin films doped with exotic elements.

Development of the Structural, Optical, and Electrical Properties of PEDOT:PSS Conducting Polymer Thin Film for Energy Applications

2021 ◽  
Vol 902 ◽  
pp. 65-70
Author(s):  
Samar Aboulhadeed ◽  
Mohsen Ghali ◽  
Mohamad M. Ayad
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Conducting Polymer ◽  
Film Surface ◽  
Volume Ratio ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Optical And Electrical Properties ◽  
Energy Applications

We report on a development of the structural, optical and electrical properties of poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) conducting polymer thin films. The PEDOT:PSS thin films were deposited by a controlled thin film applicator and their physical properties were found to be effectively modified by isopropanol. The deposited films were investigated by several techniques including XRD, UV–Vis, SPM and Hall-effect. Interestingly, by optimizing the PEDOTS:PSS/ISO volume ratio (v:v), we find that the film charge carriers type can be switched from p to n-type with a high bulk carriers concentration reaching 6×1017 cm-3. Moreover, the film surface roughness becomes smoother and reaching a small value of only 1.9 nm. Such development of the PEDOT:PSS film properties makes it very promising to act as an electron transport layer for different energy applications.

scholarly journals Positioning of the Precursor Gas Inlet in an Atmospheric Dielectric Barrier Reactor, and its Effect on the Quality of Deposited TiOx Thin Film Surface

10.14311/1767 ◽  
2013 ◽  
Vol 53 (2) ◽  
Author(s):  
Jan Píchal ◽  
Julia Klenko
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Barrier Discharge ◽  
Atmospheric Pressure ◽  
Barrier Discharge ◽  
Film Surface ◽  
Dielectric Barrier ◽  
Thin Film Surface ◽  
Atmospheric Dielectric Barrier Discharge

Thin film technology has become pervasive in many applications in recent years, but it remains difficult to select the best deposition technique. A further consideration is that, due to ecological demands, we are forced to search for environmentally benign methods. One such method might be the application of cold plasmas, and there has already been a rapid growth in studies of cold plasma techniques. Plasma technologies operating at atmospheric pressure have been attracting increasing attention. The easiest way to obtain low temperature plasma at atmospheric pressure seems to be through atmospheric dielectric barrier discharge (ADBD). We used the plasma enhanced chemical vapour deposition (PECVD) method applying atmospheric dielectric barrier discharge (ADBD) plasmafor TiOx thin films deposition, employing titanium isopropoxide (TTIP) and oxygen as reactants, and argon as a working gas. ADBD was operated in filamentary mode. The films were deposited on glass. We studied the quality of the deposited TiOx thin film surface for various precursor gas inlet positions in the ADBD reactor. The best thin films quality was achieved when the precursor gases were brought close to the substrate surface directly through the inlet placed in one of the electrodes.High hydrophilicity of the samples was proved by contact angle tests (CA). The film morphology was tested by atomic force microscopy (AFM). The thickness of the thin films varied in the range of (80 ÷ 210) nm in dependence on the composition of the reactor atmosphere. XPS analyses indicate that composition of the films is more like the composition of TiOxCy.

scholarly journals Effect of RF Power on the Properties of Sputtered-CuS Thin Films for Photovoltaic Applications

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 688 ◽  
Author(s):  
Donghyeok Shin ◽  
SangWoon Lee ◽  
Dong Ryeol Kim ◽  
Joo Hyung Park ◽  
Yangdo Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Binding Energy ◽  
Indium Tin Oxide ◽  
Short Circuit ◽  
Film Surface ◽  
Binding Energies ◽  
Tin Sulfide ◽  
Rf Power ◽  
Deposition Power

Copper sulfide (CuS) thin films were deposited on a glass substrate at room temperature using the radio-frequency (RF) magnetron-sputtering method at RF powers in the range of 40–100 W, and the structural and optical properties of the CuS thin film were investigated. The CuS thin films fabricated at varying deposition powers all exhibited hexagonal crystalline structures and preferred growth orientation of the (110) plane. Raman spectra revealed a primary sharp and intense peak at the 474 cm−1 frequency, and a relatively wide peak was found at 265 cm−1 frequency. In the CuS thin film deposited at an RF power of 40 W, relatively small dense particles with small void spacing formed a smooth thin-film surface. As the power increased, it was observed that grain size and grain-boundary spacing increased in order. The binding energy peaks of Cu 2p3/2 and Cu 2p1/2 were observed at 932.1 and 952.0 eV, respectively. Regardless of deposition power, the difference in the Cu2+ state binding energies for all the CuS thin films was equivalent at 19.9 eV. We observed the binding energy peaks of S 2p3/2 and S 2p1/2 corresponding to the S2− state at 162.2 and 163.2 eV, respectively. The transmittance and band-gap energy in the visible spectral range showed decreasing trends as deposition power increased. For the CuS/tin sulfide (SnS) absorber-layer-based solar cell (glass/Mo/absorber(CuS/SnS)/cadmium sulfide (CdS)/intrinsic zinc oxide (i-ZnO)/indium tin oxide (ITO)/aluminum (Al)) with a stacked structure of SnS thin films on top of the CuS layer deposited at 100 W RF power, an open-circuit voltage (Voc) of 115 mA, short circuit current density (Jsc) of 9.81 mA/cm2, fill factor (FF) of 35%, and highest power conversion efficiency (PCE) of 0.39% were recorded.

SYNTHESIS OF IODINE DOPED n-BMA THIN FILMS VIA PLASMA POLYMERIZATION TECHNIQUE: EFFECT ON OPTICAL PROPERTIES

2019 ◽  
Vol 27 (04) ◽  
pp. 1950133
Author(s):  
RAHIMA NASRIN ◽  
HUMAYUN KABIR ◽  
A. H. BHUIYAN
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Plasma Polymerization ◽  
Film Surface ◽  
Microscopic Analysis ◽  
Butyl Methacrylate ◽  
Root Mean Square Roughness ◽  
Iodine Doping ◽  
Thin Film Surface

In order to understand the variation of surface morphology and optical properties due to modification, an attempt has been made to synthesize iodine-doped n-butyl methacrylate thin films through plasma polymerization technique. Field emission scanning electron microscope images displayed that the surface of the modified plasma polymerized n-butyl methacrylate (PPnBMA) thin films became smooth after iodine doping. Atomic force microscopic analysis reveals that with increasing doping time from 0[Formula: see text]min to 60[Formula: see text]min the surface root-mean-square roughness value is decreased from 0.68[Formula: see text]nm to 0.51[Formula: see text]nm, which suggests that roughness of the PPnBMA thin film surface quite improved due to iodine doping. UV-Vis absorption spectroscopic analyses exhibited that iodine doping noticeably decreased both the direct and indirect energy bandgap values of PPnBMA thin film. The effect of doping by iodine on absorption coefficient, extinction coefficient, etc. of these thin films have been also discussed.

A One-Micrometer Channel Length α-Si Thin-Film Field-Effect Transistor

1984 ◽  
Vol 33 ◽  
Author(s):  
Z. Yaniv ◽  
G. Hansell ◽  
M. Vijan ◽  
V. Cannella
Keyword(s):  
Thin Film ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Liquid Crystal Displays ◽  
Channel Length ◽  
Large Area ◽  
Short Channel ◽  
Threshold Voltages ◽  
Effect Transistor ◽  
Si Thin Film

ABSTRACTA new method of fabricating short channel α-Si TFTs has been developed. One-micrometer channel length α-Si thin-film field effect transistors have been fabricated and tested. Threshold voltages as low as 1.9V and field-effect mobilities as high as 1 cm 2/V-sec are reported. These devices were fabricated by techniques compatible with the production of large area liquid crystal displays.

Laser Assisted Molecular Beam Deposition of Thin Films for Gate Dielectrics Applications

2003 ◽  
Vol 768 ◽  
Author(s):  
Robert L. DeLeon ◽  
James F. Garvey ◽  
Gary S. Tompa ◽  
Richard Moore ◽  
Harry Efstathiadis
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Molecular Beam ◽  
High Dielectric Constant ◽  
Film Surface ◽  
Rutherford Back Scattering ◽  
Molecular Beam Deposition ◽  
High Dielectric ◽  
Beam Deposition

AbstractHigh dielectric constant (k), the thermal stability and the chemical stability with respect to reaction with silicon of hafnium oxide (HfO2), and zirconium oxide (ZrO2) places them among the leading candidates for an alternative gate dielectric material. High dielectric constant HfO2 and ZrO2 thin films have successfully been deposited on silicon substrates at a temperature of 27 °C by Laser Assisted Molecular Beam Deposition (LAMBD). The LAMBD process is related to conventional Pulsed Laser Deposition (PLD). In the PLD process, the ablation plume impinges directly upon the substrate to deposit the thin film, whereas in the LAMBD process, the ablation material is expanded within a concurrently pulsed stream of a reactive gas. The gas pulse serves both to create the desired material and to transport the material to the substrate for deposition of the thin film. One advantage of the LAMBD process is that a chemically reactive carrier gas can be selected to produce the desired chemical products. Depositions yielded 35 nm to 135 nm thick HfO2, and ZrO2 films.Structural and chemical characterization of the films were performed by Auger electron spectroscopy (AES), Rutherford back-scattering (RBS), scanning electron microscopy (SEM), and x-ray diffraction (XRD). Film surface was investigated by atomic force microscopy (AFM) while optical characterization was also performed by means of spectroscopic ellipsometry (SE). Within the process window investigated, the film Hf/O and Zr/O ratios was found to be in the range 0.6 to 1.2. The as deposited films were amorphous with refraction index (RI) at 623 nm wavelength films in the range of 1.22 to 1.27 for the HfO2 and in the range of 1.23 to 1.19 for the ZrO2 films.

scholarly journals Unique Surface Modifications on Diamond Thin Films

2021 ◽  
Author(s):  
Vadali Venkata Satya Siva Srikanth
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Surface ◽  
Surface Modifications ◽  
Surface Patterning ◽  
Chemical Surface ◽  
Thin Film Surface ◽  
Diamond Thin Film ◽  
Diamond Thin Films ◽  
Chemical Surface Modifications

Diamond thin films are touted to be excellent in surface-sensitive sensing, electro-mechanical systems, and electrochemical applications. However, these applications often entail patterned active surfaces and subtle chemical surface modifications. But due to diamond’s intrinsic hardness and chemical inertness, surface patterning (using micro-machining and ion etching) and chemical surface modifications, respectively, are very difficult. In the case of surface patterning, it is even more challenging to obtain patterns during synthesis. In this chapter, the direct patterning of sub-wavelength features on diamond thin film surface using a femtosecond laser, rapid thermal annealing as a means to prepare the diamond thin film surface as an efficient direct charge transfer SERS substrate (in metal/insulator/semiconductor (MIS) configuration), and implantation of 14N+ ions into the surface and sub-surface regions for enhancing the electrical conductivity of diamond thin film to a certain depth (in MIS configuration) will be discussed encompassing the processing strategies and different post-processing characteristics.

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