scholarly journals Fabrication of Ultraviolet Photodetectors Based on Fe-Doped ZnO Nanorod Structures

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3861 ◽  
Author(s):  
Yen-Lin Chu ◽  
Sheng-Joue Young ◽  
Liang-Wen Ji ◽  
I-Tseng Tang ◽  
Tung-Te Chu
Keyword(s):  
Seed Layer ◽  
Hexagonal Wurtzite Structure ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
Zno Films ◽  
Diffraction Spectrum ◽  
Glass Substrates ◽  
Uv Illumination ◽  
Temperature Solution ◽  
Doped Zno

In this paper, 100 nm-thick zinc oxide (ZnO) films were deposited as a seed layer on Corning glass substrates via a radio frequency (RF) magnetron sputtering technique, and vertical well-aligned Fe-doped ZnO (FZO) nanorod (NR) arrays were then grown on the seed layer-coated substrates via a low-temperature solution method. FZO NR arrays were annealed at 600 °C and characterized by using field emission scanning microscopy (FE-SEM) and X-ray diffraction spectrum (XRD) analysis. FZO NRs grew along the preferred (002) orientation with good crystal quality and hexagonal wurtzite structure. The main ultraviolet (UV) peak of 378 nm exhibited a red-shifted phenomenon with Fe-doping by photoluminescence (PL) emission. Furthermore, FZO photodetectors (PDs) based on metal–semiconductor–metal (MSM) structure were successfully manufactured through a photolithography procedure for UV detection. Results revealed that compared with pure ZnO NRs, FZO NRs exhibited a remarkable photosensitivity for UV PD applications and a fast rise/decay time. The sensitivities of prepared pure ZnO and FZO PDs were 43.1, and 471.1 for a 3 V applied bias and 380 nm UV illumination, respectively.

EFFECTS OF SUBSTRATE TEMPERATURE ON THE DOPING CHARACTERISTICS OF Li-W CO-DOPED ZnO FILMS

2014 ◽  
Vol 21 (01) ◽  
pp. 1450003 ◽  
Author(s):  
YUEHUI HU ◽  
YICHUAN CHEN ◽  
XIAOHUA ZHANG ◽  
DEFU MA ◽  
JUNXIANG WANG ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Film Surface ◽  
Hexagonal Wurtzite Structure ◽  
Rf Magnetron Sputtering ◽  
Optical Transmittance ◽  
Zno Films ◽  
Glass Substrates ◽  
Doped Zno ◽  
Xrd Patterns ◽  
Co Doped

Li - W co-doped ZnO (LWZO) thin films were deposited on quartz glass substrates by RF magnetron sputtering technology. The properties of LWZO films deposited with varied substrate temperatures were investigated. When the substrate temperature was lower than 120°C — according to X-ray diffraction (XRD) patterns, films keep hexagonal wurtzite structure with the (002) plane as preferred orientation — the optical transmittance was higher than 85%. When the substrate temperature was higher than 120°C, the results of XPS and XRD show that W 6+ will work as donors, and the (101) peak appeared; the optical transmittance decreased slightly but still higher than 82%. Scanning electron microscope (SEM) and its two-dimensional Fourier transform images showed that films had smooth surface and columnar particles structure when the substrate temperature was lower than 120°C. The film surface became rougher and flaky-shaped particles structure could be observed when the substrate temperature was higher than 120°C. In addition, the lowest electrical resistivity of sample was 3.6 × 10-3 Ω ⋅ cm which was obtained at substrate temperature 240°C.

scholarly journals Structural, Optical and Electrical Properties of Cu doped ZnO Thin Films Grown by RF Magnetron Sputtering: Application to Solar Photocatalysis

2021 ◽  
Author(s):  
Bilel Khalfallah ◽  
I. Riahi ◽  
F. Chaabouni
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Hexagonal Wurtzite Structure ◽  
Rf Magnetron Sputtering ◽  
Zno Thin Films ◽  
Bandgap Energy ◽  
Glass Substrates ◽  
Zno Powders ◽  
Doped Zno ◽  
Spectroscopy Studies

Abstract RF sputtered undoped and Cu doped ZnO (CZO) thin films were deposited on unheated glass substrates using a mixed Cu2O and ZnO powders target at different Cu concentrations of 0, 1, 2, 3 and 4 wt.%. The effects of copper concentration on the structural, electrical, optical and photocatalytic properties of CZO films have been studied. From XRD and Raman spectroscopy studies, it was found that the deposited films were polycrystalline with a predominant hexagonal wurtzite structure along the c-axis perpendicular to the substrate surface. The presence of multiple interference fringes in the transmittance and reflectance spectra shows the good homogeneity of the films. All the films are highly transparent with transparency reaching 80% indicating the possibility to use these films as an optical window. The absorption tail gradually shifted towards a higher wavelength side, which resulted in the decrease of bandgap energy from 3.35 to 3.26 eV. All the sputtered films are highly conductive with a conductivity reaching 104 S.cm− 1.The effect of Cu-doping on the photocatalytic activity of ZnO thin films for the degradation of methylene blue (MB) dye was studied under sunlight irradiation and the results showed that the Cudoping provokes appreciable degradation of MB and reached a maximum for the 1 wt.% Cu doped ZnO film.

Effect of Substrate Temperature on the Properties of Al-Doped ZnO Films by RF Magnetron Sputtering

2010 ◽  
Vol 663-665 ◽  
pp. 1293-1297 ◽  
Author(s):  
Yue Bo Wu ◽  
Sheng Lei ◽  
Zhe Wang ◽  
Ru Hai Zhao ◽  
Lei Huang ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Substrate Temperature ◽  
Visible Region ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
Axis Orientation ◽  
Glass Substrates ◽  
Higher Temperature ◽  
Doped Zno ◽  
Substrate Temperatures

The Al-doped ZnO (AZO) films were deposited on the glass substrates by RF magnetron sputtering at different substrate temperatures. The effect of substrate temperature on the structural, optical, and electrical properties of AZO films was investigated. The results indicate each of the films has a preferential c-axis orientation. The grain size increases with substrate temperature increasing. All the films exhibit a high transmittance in visible region and have sharp ultraviolet absorption characteristics. The resistivity decreases with substrate temperature increasing up to 250oC, then increases for higher temperature.

Ultraviolet Photoresponse of Pure and Al doped ZnO Polycrystalline Thin Films by Inkjet Printing

2009 ◽  
Vol 1161 ◽  
Author(s):  
Yan Wu ◽  
Takahiko Tamaki ◽  
Wolfgang Voit ◽  
Lyubov M. Belova ◽  
K. V. Rao
Keyword(s):  
Thin Films ◽  
Uv Irradiation ◽  
Inkjet Printing ◽  
Hexagonal Wurtzite Structure ◽  
Zno Films ◽  
Acetate Solution ◽  
Glass Substrates ◽  
Polycrystalline Thin Films ◽  
Decay Times ◽  
Doped Zno

AbstractPure ZnO, and Al doped ZnO, 120 -300 nm thin films on glass substrates, were synthesized by inkjet printing technique using zinc and aluminum acetate solution as precursors and a two stage heat treatment process to obtain polycrystalline hexagonal wurtzite structure with the mean grain size of 25 and 30 nm respectively. All films exhibit a transmittance above 85-90% in the visible wavelength range below 700 nm. In the Al doped films the UV absorption spectra show a strong absorption onset below 380nm followed by shoulders centered around 325 nm depending on the film thickness. The electrical conductivity of Al doped ZnO thin films is larger by two orders of magnitude than that for pure ZnO films while the photoconductivity increases by about three orders of magnitude under UV irradiation. The photoresponse of the films with UV irradiation in terms of the rise and decay times in the frequency range from 5 to 500 Hz is also presented and discussed.

scholarly journals FESEM, XRD and DRS studies of electrochemically deposited boron doped ZnO films

2018 ◽  
Vol 35 (4) ◽  
pp. 824-829 ◽  
Author(s):  
Yasemin Caglar ◽  
Saliha Ilican ◽  
Mujdat Caglar
Keyword(s):  
Surface Morphology ◽  
Band Gap ◽  
Optical Band Gap ◽  
Hexagonal Wurtzite Structure ◽  
Bath Temperature ◽  
Xrd Analysis ◽  
Zno Films ◽  
Si Substrates ◽  
Doped Zno ◽  
B Doping

Abstract In this study, the effect of boron (B) incorporation into zinc oxide (ZnO) has been investigated. The undoped, 2 at.%. and 4 at.% B doped ZnO films were deposited on p-type silicon (Si) substrates by electrodeposition method using chronoamperometry technique. Electrochemical depositions were performed by applying a constant potentiostatic voltage of 1.1 V for 180 min at 90 °C bath temperature. To analyze the surface morphology, field emission scanning electron microscopy (FESEM) was used and the results revealed that while a small amount of boron resulted in smoother surface, a little more incorporation of boron changed the surface morphology to dandelion-like shaped rods on the whole surface. By using X-ray diffraction (XRD) analysis, the crystal structures of the films were detected and the preferred orientation of the ZnO, which exhibited polycrystalline and hexagonal wurtzite structure, changed with B doping. For the estimation of the optical band gap of obtained films, UV-Vis diffuse reflectance spectra (DRS) of the films were taken at room temperature and these data were applied to the Kubelka-Munk function. The optical band gap of ZnO narrowed due to incorporation of B, which was confirmed by red-shift.

Substrate Temperature Effects on the Structural and Optical Properties of TiO2-Doped ZnO Films for Organic Photovoltaic Devices

2013 ◽  
Vol 275-277 ◽  
pp. 1964-1967 ◽  
Author(s):  
T. Zhang ◽  
Z.Y. Zhong ◽  
J. Zhou ◽  
F.L. Sun
Keyword(s):  
Optical Properties ◽  
Substrate Temperature ◽  
Crystallite Size ◽  
Rf Magnetron Sputtering ◽  
Optical Transmittance ◽  
Optical Bandgap ◽  
Zno Films ◽  
Glass Substrates ◽  
Doped Zno ◽  
Deposited Films

TiO2-doped ZnO thin films with highly (002)-preferred orientation were grown on glass substrates by RF magnetron sputtering. The effect of substrate temperature on structure and optical properties of the films were investigated by X-ray diffractometer and spectrophotometer. The results show that the polycrystalline TiO2-doped ZnO films consist of the hexagonal crystal structures with c-axis as the preferred growth orientation normal to the substrate. The substrate temperature significantly affects the crystallite size and optical transmittance of the deposited films, but slightly influences the refractive index and optical bandgap of the deposited films. The TiO2-doped ZnO film grown at substrate temperature of 470 K possesses the maximum crystallite size, an average transmittance of 76.2 % in the visible light range, and an optical bandgap of 3.46 eV.

Dependence of Film Thickness on Properties of Al Doped ZnO Thin Films

2011 ◽  
Vol 194-196 ◽  
pp. 2305-2311
Author(s):  
Ying Ge Yang ◽  
Dong Mei Zeng ◽  
Hai Zhou ◽  
Wen Ran Feng ◽  
Shan Lu ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Electrical Parameter ◽  
Substrate Surface ◽  
Rf Magnetron Sputtering ◽  
Thickness Effect ◽  
Visible Range ◽  
Glass Substrates ◽  
Doped Zno

In this study high quality of Al doped ZnO (ZAO) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature in order to study the thickness effect upon their structure, electrical and optical properties. XRD results show that the films are polycrystalline and with strongly preferred (002) orientation perpendicular to substrate surface whatever the thickness is. The crystallite size was calculated by Williamson-Hall method, while it increases as the film thickness increased. The lattice stress is mainly caused by the growth process. Hall measurements revealed electrical parameter very dependent upon thickness when the thickness of ZAO film is lower than 700 nm. The resistivity decreased and the carrier concentration and Hall mobility increases as the film thickness increased. When film thickness becomes larger, only a little change in the above properties was observed. All the films have high transmittance above 90% in visible range. Red shift of the absorption edge was observed as thickness increased. The optical energy bandgap decreased from 3.41eV to 3.30 eV with the increase of film thickness.

Preparation and Characterization of Zn1-XMnxO Thin Films on SiO2 Substrates

2012 ◽  
Vol 560-561 ◽  
pp. 820-824
Author(s):  
Yue Zhi Zhao ◽  
Fei Xiong ◽  
Guo Mian Gao ◽  
Shi Jing Ding
Keyword(s):  
Thin Films ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Flat Surfaces ◽  
Atomic Force ◽  
Mn Content ◽  
Doped Zno ◽  
Mn Doped

Mn-doped ZnO thin films were prepared on SiO2substrates by using a radio-frequency(rf) magnetron sputtering in order to investigate structure and optical proprieties of the films. X-ray diffraction (XRD), Atomic force microscope (AFM) and UV-VIS spectrophotometry were employed to characterize the Mn-doped ZnO films. The results showed that the shape of the XRD spectrum was remarkably similar to that of the un-doped ZnO film; the film had mainly (002) peak, and indicate that the structure of the films was not disturbed by Mn-doped. The film had rather flat surfaces with the peak-to-tail roughness of about 25nm. Mn-doping changed the band gap of the films, which increased with the increase of the Mn content.

The Resistive Switching Behavior of ZnO Films Depending on Li Dopant Concentration and Electrode Materials

2016 ◽  
Vol 99 ◽  
pp. 75-80
Author(s):  
Arsen Igityan ◽  
Yevgenia Kafadaryan ◽  
Natella Aghamalyan ◽  
Silva Petrosyan
Keyword(s):  
Resistive Switching ◽  
Electrode Materials ◽  
Switching Behavior ◽  
Zno Films ◽  
Lithium Content ◽  
Resistive Switching Behavior ◽  
Bipolar Resistive Switching ◽  
Glass Substrates ◽  
Ohmic Behavior ◽  
Doped Zno

Lithium (0, 1.0 and 10 at.%)-doped ZnO (LiZnO) polycrystalline thin films were deposited on Pt/SiO2, LaB6/Al2O3, Au/SiO2 and 20 at.% fluorine-doped SnO2(FTO)/glass substrates by an e-beam evaporation method. Metal/LiZnO/Metal sandwich structures were constructed by depositing different top electrodes (Ag, Al and Au) to find memristive characteristics depending on the lithium content and electrode materials. Compared with undoped and 1%Li-doped ZnO devices, the 10 at.%Li-doped ZnO (10LiZnO) device exhibits resistive switching memory. The Ag/10LiZnO/Pt and Ag/10LiZnO/LaB6 memory devices exhibit unipolar resistive switching behavior while bipolar resistive switching in Ag/10LiZnO/FTO, Au/10LiZnO/FTO and Al/10LiZnO/LaB6 structures is revealed. The dominant conduction mechanisms are explained in terms of Ohmic behavior, space charge limited current (SCLC) and Schottky emission for the URS and BRS behaviors.

Sign in / Sign up

Export Citation Format

Share Document