scholarly journals The thermoelectric properties of Au nanoparticle-incorporated Al-doped mesoporous ZnO thin films

2019 ◽  
Vol 6 (5) ◽  
pp. 181799 ◽  
Author(s):  
Min-Hee Hong ◽  
Wooje Han ◽  
Kyu-Yeon Lee ◽  
Hyung-Ho Park
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Conductivity ◽  
Pore Structure ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Al Doping ◽  
Au Nps ◽  
Mesoporous Zno ◽  
Pore Arrangement

Mesoporous Al-doped ZnO thin films incorporated with gold nanoparticles (Au NPs) were synthesized using a sol–gel and evaporation-induced self-assembly process. In this study, the complementary effects of Au NP incorporation and Al doping on the thermoelectric properties of mesoporous ZnO thin films were analysed. The incorporated Au NPs induced an increase in electrical conductivity but a detriment in the pore arrangement of the mesoporous ZnO thin film, which was accompanied by a decrease in porosity. However, the addition of the Al dopant minimized the pore structural collapse because of the inhibition of the grain growth in the ZnO skeletal structure, resulting in the enhancement of the pore arrangement and porosity. When the Au NPs and Al dopant were added at the same time, the degradation in the pore structure was minimized and the electrical conductivity was effectively increased, but the absolute value of the Seebeck coefficient was decreased. However, as a result, the thermoelectric power factor was increased by 2.4 times compared to that of the pristine mesoporous ZnO thin film. It was found that co-introducing the Au NPs and Al doping to the mesoporous ZnO structure was effective in preserving the pore structure and increasing the electric conductivity, thereby enhancing the thermoelectric property of the mesoporous ZnO thin film.

scholarly journals Thermoelectric Properties of Al-Doped Mesoporous ZnO Thin Films

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Min-Hee Hong ◽  
Chang-Sun Park ◽  
Won-Seon Seo ◽  
Young Soo Lim ◽  
Jung-Kun Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Grain Growth ◽  
Self Assembly ◽  
Doping Concentration ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Zno Thin Films ◽  
Al Doping ◽  
Mesoporous Zno

Al-doped mesoporous ZnO thin films were synthesized by a sol-gel process and an evaporation-induced self-assembly process. In this work, the effects of Al doping concentration on the electrical conductivity and characterization of mesoporous ZnO thin films were investigated. By changing the Al doping concentration, ZnO grain growth is inhibited, and the mesoporous structure of ZnO is maintained during a relatively high temperature annealing process. The porosity of Al-doped mesoporous ZnO thin films increased slightly with increasing Al doping concentration. Finally, as electrical conductivity was increased as electrons were freed and pore structure was maintained by inhibiting grain growth, the thermoelectric property was enhanced with increasing Al concentration.

scholarly journals Effects of Thermal Annealing on the Characteristics of High Frequency FBAR Devices

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 397
Author(s):  
Yu-Chen Chang ◽  
Ying-Chung Chen ◽  
Bing-Rui Li ◽  
Wei-Che Shih ◽  
Jyun-Min Lin ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Annealing ◽  
Electromechanical Coupling ◽  
Zno Thin Films ◽  
Electromechanical Coupling Coefficient ◽  
Back Side ◽  
Zno Thin Film ◽  
Frequency Responses ◽  
Sputtering System

In this study, piezoelectric zinc oxide (ZnO) thin film was deposited on the Pt/Ti/SiNx/Si substrate to construct the FBAR device. The Pt/Ti multilayers were deposited on SiNx/Si as the bottom electrode and the Al thin film was deposited on the ZnO piezoelectric layer as the top electrode by a DC sputtering system. The ZnO thin film was deposited onto the Pt thin film by a radio frequency (RF) magnetron sputtering system. The cavity on back side for acoustic reflection of the FBAR device was achieved by KOH solution and reactive ion etching (RIE) processes. The crystalline structures and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optimized as-deposited ZnO thin films with preferred (002)-orientation were obtained under the sputtering power of 80 W and sputtering pressure of 20 mTorr. The crystalline characteristics of ZnO thin films and the frequency responses of the FBAR devices can be improved by using the rapid thermal annealing (RTA) process. The optimized annealing temperature and annealing time are 400 °C and 10 min, respectively. Finally, the FBAR devices with structure of Al/ZnO/Pt/Ti/SiNx/Si were fabricated. The frequency responses showed that the return loss of the FBAR device with RTA annealing was improved from −24.07 to −34.66 dB, and the electromechanical coupling coefficient (kt2) was improved from 1.73% to 3.02% with the resonance frequency of around 3.4 GHz.

Plasma Pre-Treatment of Polyethylene Terephthalate Substrate Influence on the Properties of ZnO Thin Film

2014 ◽  
Vol 895 ◽  
pp. 41-44
Author(s):  
Seiw Yen Tho ◽  
Kamarulazizi Ibrahim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Polyethylene Terephthalate ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Water Contact ◽  
Pre Treatment ◽  
Pet Substrate

In this work, the influences of plasma pre-treatment on polyethylene terephthalate (PET) substrate to the properties of ZnO thin film have been carried out. ZnO thin films were successfully grown on PET substrate by spin coating method. In order to study the effects of plasma pre-treatment, a comparison of treated and untreated condition was employed. Water contact angle measurement had been carried out for PET wettability study prior to ZnO thin film coating. Morphology study of ZnO thin film was performed by scanning probe microscope (SPM). Besides, optical study of the ZnO thin film was done by using UV-vis spectrophotometer. All the measured results show that plasma pre-treatment of PET substrate plays an important role in enhancing the wettability of PET and optical properties of the ZnO thin films. In conclusion, pre-treatment of PET surface is essential to produce higher quality ZnO thin film on this particular substrate in which would pave the way for the integration of future devices.

Enhanced UV Photon-response of Tin Nano Cluster Loaded- laser Irradiated ZnO Thin film detector

2011 ◽  
Vol 1288 ◽  
Author(s):  
Rashmi Menon ◽  
K. Sreenivas ◽  
Vinay Gupta
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Surface States ◽  
Response Speed ◽  
Rf Magnetron Sputtering ◽  
Fast Response ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Photo Response

ABSTRACTZinc Oxide (ZnO), II-VI compound semiconductor, is a promising material for ultraviolet (UV) photon sensor applications due to its attractive properties such as good photoconductivity, ease processing at low temperatures and excellent radiation hardness. The rf magnetron sputtering is a suitable deposition technique due to better control over stoichiometry and deposition of uniform film. Studies have shown that the presence of surface defects in ZnO and subsequently their passivation are crucial for enhanced photo-response characteristics, and to obtain the fast response speed. Worldwide efforts are continuing to develop good quality ZnO thin films with novel design structures for realization of an efficient UV photon sensor. In the present work, UV photon sensor is fabricated using a ZnO thin films deposited by rf magnetron sputtering on the corning glass substrate. Photo-response, (Ion/Ioff) of as-grown ZnO film of thickness 100 nm is found to be 3×103 with response time of 90 ms for UV intensity of 140 μW/cm2 (λ = 365 nm). With irradiation on ZnO thin film by pulsed Nd:YAG laser (forth harmonics 266 nm), the sensitivity of the UV sensor is found to enhance. The photo-response increases after laser irradiation to 4x104 with a fast response speed of 35 ms and attributed to the change in surface states and the native defects in the ZnO thin film. Further, enhancement in the ultraviolet (UV) photo-response (8×104) of detector was observed after integrating the nano-scale islands of Sn metal on the surface of laser irradiated ZnO thin film.

ELECTRICAL AND OPTICAL PROPERTIES OF ZnO THIN FILMS PREPARED BY R.F. MAGNETRON SPUTTERING

2011 ◽  
Vol 25 (20) ◽  
pp. 2741-2749 ◽  
Author(s):  
J. C. ZHOU ◽  
L. LI ◽  
L. Y. RONG ◽  
B. X. ZHAO ◽  
Y. M. CHEN ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Oxide Thin Film ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Electrical And Optical Properties ◽  
Axis Orientation ◽  
Sputtering Power

High transparency and conductivity of transparent conducting oxide thin film are very important for improving the efficiency of solar cells. ZnO thin film is a better candidate for transparent conductive layer of solar cell. N-type ZnO thin films were prepared by radio-frequency magnetron sputtering on glass substrates. ZnO thin films underwent annealing treatment after deposition. The influence of the sputtering power on the surface morphology, the electrical and optical properties were studied by AFM, XRD, UV2450 and HMS-3000. The experimental results indicate that the crystal quality of ZnO thin film is improved and all films show higher c-axis orientation with increasing sputtering power from 50 to 125 W. The average transparency of ZnO thin films is higher than 90% in the range of 400–900 nm between the sputtering power of 50–100 W. After the rapid thermal annealing at 550°C for 300 s under N2 ambient, the minimum resistivity reach to 10-2Ω⋅ cm .

Effect of Sintering Atmosphere on the Electrical and Thermal Properties of Al-Doped ZnO Thin Films Prepared Using Inkjet Printing Method

2015 ◽  
Vol 793 ◽  
pp. 440-444
Author(s):  
J.H. Lim ◽  
Cheow Keat Yeoh ◽  
Chik Abdullah ◽  
Pei Leng Teh
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Thermal Properties ◽  
Inkjet Printing ◽  
Zno Thin Films ◽  
Al Doping ◽  
Sintering Atmosphere ◽  
Ink Jet ◽  
Jet Printing ◽  
Doped Zno

Al-doped ZnO thin films were prepared by ink-jet printing and their electrical and thermal properties with different amounts of Al doping and sintering atmosphere were investigated. The XRD traces of films show the doped materials did not form additional crystalline phases with increasing amounts of Al doping. Electrical conductivity of film increased from 4.86 S/cm to 120.94 S/cm as the amounts of Al doping increased from 0 wt% to 4 wt%. However, the thermal conductivity decreased from 24 W/mK to 13 W/mK with increasing the Al doping from 0 wt% to 4 wt%. The electrical conductivity of film shows higher values sintered in vacuum (120.94 S/cm) compared to film sintered in air (114.1 S/cm).

Effect of RF Power on the Formation and Morphology Evolution of ZnO Nanostructured Thin Films

2012 ◽  
Vol 576 ◽  
pp. 577-581 ◽  
Author(s):  
N.D.M. Sin ◽  
Mohamad Hafiz Mamat ◽  
Mohamed Zahidi Musa ◽  
S. Ahmad ◽  
A. Abdul Aziz ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Properties ◽  
Zno Thin Films ◽  
Morphology Evolution ◽  
Zno Thin Film ◽  
Rf Power ◽  
Nanostructured Thin Films ◽  
Atomic Force ◽  
Current Voltage

The effect of RF power on the formation and morphology evolution of ZnO nanostructured thin films deposited by magnetron sputtering are presented. This project focused on electrical, optical and structural properties of ZnO thin films. The effect of variation of RF power at 50 watt-250 watt at 200 °C on glass substrate of the ZnO thin films was investigated. The thin films were examined for electrical properties and optical properties using two point probe current-voltage (I-V) measurement (Keithley 2400) and UV-Vis-NIR spectrophotometer (JASCO 670) respectively. The structural properties were characterized using field emission scanning electron microscope (FESEM) (JEOL JSM 7600F) and atomic force microscope (AFM) (Park System XE-100). The IV measurement indicated that at RF power 200 watt the conductivity of ZnO thin film show the highest. All films show high UV absorption properties using UV-VIS spectrophotometer (JASCO 670). The root means square (rms) roughness for ZnO thin film were about 4 nm measured using AFM. The image form FESEM observed that transformation of structure size started to change as the RF power increase.

Silver Doped Zinc Oxide Thin Film Production by Thermionic Vacuum Arc (TVA) Technique

2021 ◽  
Vol 43 (3) ◽  
pp. 253-253
Author(s):  
Mehmet zkan Mehmet zkan ◽  
Sercen Sadik Erdem Sercen Sadik Erdem
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Zinc Oxide ◽  
Band Gap ◽  
Glass Substrate ◽  
Zno Thin Films ◽  
Vacuum Arc ◽  
Zno Thin Film ◽  
Doped Zno ◽  
Thermionic Vacuum Arc

In this paper, silver (Ag)doped Zinc Oxide(ZnO) thin films were prepared on glass and silicon substrate by using a thermionic vacuum arc technique. The surface, structural, optical characteristics of silver doped thin films have been examined by X-Ray diffractometer (XRD), field emission scanning emission electron microscopy (FESEM), atomic force microscopy (AFM), and UV-Visible spectrophotometer. As a result of these measurements, Ag, Zn and ZnO reflection planes were determined for thin films formed on Si and glass substrate. Nano crystallites have emerged in FESEM and AFM images. The produced films have low transparency. The optical band gap values were measured by photoluminescence devices at room temperature for thin films produced on silicon and glass substrate. The band gap values are very close to 3.10 eV for Ag doped ZnO thin films. The band gap of un-doped ZnO thin film is approximately 3.3 eV. It was identified that Ag doped changes the properties of the ZnO thin film.

Effect of Oxygen Flow Rate on the Properties of Nanocolumnar ZnO Thin Films Prepared Using Radio Frequency Magnetron Sputtering System for Ultraviolet Sensor Applications

2011 ◽  
Vol 364 ◽  
pp. 1-6 ◽  
Author(s):  
Mohamad Hafiz Mamat ◽  
Syafinaz Wan Anwar Wan ◽  
Mohamed Zahidi Musa ◽  
Zuraida Khusaimi ◽  
Mohd Firdaus Malek ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Oxygen Flow Rate ◽  
Oxygen Flow ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Flow Rates ◽  
Sensor Applications ◽  
Ultraviolet Sensor ◽  
Sputtering System

Nanostructured zinc oxide (ZnO) thin films were deposited on glass substrates using radio frequency (RF) magnetron sputtering system at different oxygen flow rates ranges between 0 to 40 sccm. Field emission scanning electron microscopy (FESEM) images was revealed that nanocolumnar ZnO structure thin films are produced on the substrates using high purity ZnO as the target at RF power of 250 W in the argon and oxygen gas mixture ambient. The XRD spectra reveal that the deposited films are preferentially grown along the c-axis indicating high ZnO crystallinity. The ultraviolet-visible (UV-Vis) spectra show that all samples are very transparent in the visible region (400 – 800 nm) with average transparency above 80 %. The photocurrent properties indicate that ZnO thin film prepared at oxygen flow rate of 20 sccm has the optimum characteristic for ultraviolet sensor applications. This finding suggested that the oxygen flow rates play important role and has critical value for semiconducting nanocolumnar ZnO growth in the sputtering system, which can produce ZnO thin film with high sensitivity of ultraviolet detection.

scholarly journals Effect of thickness on the optical properties of ZnO thin films prepared by pulsed laser deposition technique (PLD)

2019 ◽  
Vol 15 (32) ◽  
pp. 114-121
Author(s):  
Maysar A. Salim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Film Thickness ◽  
Energy Gap ◽  
Transparent Conducting Oxide ◽  
Zno Thin Films ◽  
Zno Films ◽  
Zno Thin Film ◽  
Optical Energy Gap

Zinc Oxide (ZnO) thin films of different thickness were preparedon ultrasonically cleaned corning glass substrate, by pulsed laserdeposition technique (PLD) at room temperature. Since mostapplication of ZnO thin film are certainly related to its opticalproperties, so the optical properties of ZnO thin film in thewavelength range (300-1100) nm were studied, it was observed thatall ZnO films have high transmittance (˃ 80 %) in the wavelengthregion (400-1100) nm and it increase as the film thickness increase,using the optical transmittance to calculate optical energy gap (Egopt)show that (Egopt) of a direct allowed transition and its value nearlyconstant (~ 3.2 eV) for all film thickness (150, 180, 210, and 240)nm, so Zn0 thin films were used as a transparent conducting oxide(TCO) in various optoelectronic application such as a window in athin film solar cells.

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