scholarly journals Mechanism and Optimized Process Conditions of Forming One-Dimensional ZnO Nanorods with Al-Doping by Electrodeposition Method

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jianlin Chen ◽  
Yu Zhang ◽  
Wei Qiu ◽  
Shu Chen ◽  
Chang Liu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Deposition Time ◽  
Light Trapping ◽  
Zno Nanorods ◽  
Light Transmittance ◽  
Process Conditions ◽  
Al Doping ◽  
One Dimensional ◽  
Electrodeposition Method ◽  
Doped Zno

Textured transparent conductive electrodes for thin-film solar cells have been considered as an effective route for enhancing sunlight harvest due to light trapping. Here, we report a self-assembling electrochemical approach for preparing Al-doped ZnO nanorod arrays (NRAs) as light-trapping electrodes from a mixed aqueous solution of zinc nitrate and aluminium nitrate. The mechanism and optimized process conditions of forming one-dimensional ZnO nanorods with Al-doping were systematically investigated. The results showed that Al atoms were successfully doped into ZnO crystal lattice, and the morphologies could be controlled by adjusting the Al3+/Zn2+ ratio in the precursors and deposition time. The Al-doped ZnO films grew into well-aligned hexagonal NRAs with c-axis perpendicular to the substrates and then transited into a mixture of nanosheets and nanorods with Al3+/Zn2+ ratio increasing. They exhibited good electrical conductivity with a sheet resistance of 68-167Ω/square and appropriate visible light transmittance of 61-82%. Taking into account of desired morphology and phase purity, as well as good electrical conductivity and optical transmittance, the optimal window of Al3+/Zn2+ ratio in the precursors was determined between 1 at% and 2 at% with applied potential of -1.5V, bath temperature of 80°C, and deposition time of about 30min. The electrodeposition method provides a facile and efficient route for obtaining large-area textured transparent electrodes at a low cost.

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).

Fabrication and Thermoelectric Properties of Al-Doped (ZnO)5In2O3 by Microwave Heating

2013 ◽  
Vol 761 ◽  
pp. 27-31 ◽  
Author(s):  
Tomoyuki Endo ◽  
Yamato Hayashi ◽  
Jun Fukushima ◽  
Hirotsugu Takizawa
Keyword(s):  
Electrical Conductivity ◽  
Microwave Heating ◽  
The Other ◽  
Conventional Heating ◽  
High Electrical Conductivity ◽  
Templated Grain Growth ◽  
Al Doping ◽  
Xrd Pattern ◽  
Doped Zno ◽  
Absolute Seebeck Coefficient

Various (ZnO)5In2O3ceramics were fabricated by microwave heating. Density, XRD pattern and microstructure were examined and those of Al-doped (ZnO)5In2O3were almost the same as Al-free one. Highly textured (ZnO)5In2O3ceramic was also fabricated by reactive templated grain growth (RTGG) method. The electrical conductivity was not improved by Al-doping; however it was improved slightly by microwave heating compared with conventional heating and especially improved by texturing using RTGG method. On the other hand, the absolute Seebeck coefficient in microwave heating was improved about 25% by Al-doped. Maximum electric power factor of textured specimen fabricated by RTGG method along ab-plane showed 5.76×10-4WK-2m-1(at 873K), which was attributed to high electrical conductivity.

MAGNETIC PROPERTIES OF ONE-DIMENSIONAL Sm-DOPED ZnO NANOSTRUCTURES FABRICATED BY HYDROTHERMAL METHOD

2013 ◽  
Vol 27 (22) ◽  
pp. 1350161 ◽  
Author(s):  
C. C. LIN ◽  
C. Y. KUNG ◽  
S. L. YOUNG ◽  
H. Z. CHEN ◽  
M. C. KAO ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Zno Nanorods ◽  
Magnetization Measurement ◽  
Hexagonal Structure ◽  
Diffraction Peak ◽  
Zno Nanostructures ◽  
One Dimensional ◽  
Doped Zno ◽  
Single Diffraction ◽  
Xrd Patterns

Well-defined ZnO and Sm -doped nanorods have been successfully fabricated by a low temperature hyderthermal process. The XRD patterns of both compositions with single diffraction peak (002) show the same wurtzite hexagonal structure. The radius of Sm - ZnO nanorods observed by FE-SEM is smaller than that of pure ZnO indicating the reduction of growth rate by the doping of Sm . Ferromagnetism is observed from the results of magnetization measurement. The increase of the saturation magnetization and decrease of coercivity reveal an association with the increase of oxygen vacancies induced by the doping of the Sm in the nanorods.

Magnetic and optical property studies on controlled low-temperature fabricated one-dimensional Cr doped ZnO nanorods

CrystEngComm ◽  
2010 ◽  
Vol 12 (6) ◽  
pp. 1887 ◽  
Author(s):  
G. Mohan Kumar ◽  
P. Ilanchezhiyan ◽  
Jin Kawakita ◽  
M. Subramanian ◽  
R. Jayavel
Keyword(s):  
Optical Property ◽  
Low Temperature ◽  
Zno Nanorods ◽  
One Dimensional ◽  
Doped Zno

Diffusion-Driven Al-Doping of ZnO Nanorods and Stretchable Gas Sensors Made of Doped ZnO Nanorods/Ag Nanowires Bilayers

2018 ◽  
Vol 11 (1) ◽  
pp. 1411-1419 ◽  
Author(s):  
Gitae Namgung ◽  
Qui Thanh Hoai Ta ◽  
Woochul Yang ◽  
Jin-Seo Noh
Keyword(s):  
Gas Sensors ◽  
Zno Nanorods ◽  
Al Doping ◽  
Ag Nanowires ◽  
Doped Zno

scholarly journals Characterization of Al-doped ZnO nanorods grown by chemical bath deposition method

2018 ◽  
Vol 6 (1) ◽  
pp. 1-9
Author(s):  
Sabah M. Ahmed
Keyword(s):  
Metal Oxide ◽  
Gas Sensors ◽  
Zno Nanorods ◽  
Metal Oxide Semiconductors ◽  
Al Doping ◽  
Oxide Semiconductors ◽  
X Ray ◽  
Glass Substrates ◽  
Doped Zno ◽  
Doping Ratio

Introduction: In recent years a metal oxide semiconductors have been paid attention due to their excellent chemical and physical properties. ZnO (Zinc oxide) is considered as one of the most attractive semiconductor materials for implementation in photo-detectors, gas sensors, photonic crystals, light emitting diodes, photodiodes, and solar cells, due to its novel electrical and optoelectronic properties. There are different uses of metal oxide semiconductors such us, UV photodetectors which are useful in space research’s, missile warning systems, high flame detectors, air quality spotting, gas sensors, and precisely calculated radiation for the treatment of UV-irradiated skin. ZnO is a metal oxide semiconductors and it is used as a transparent conducting oxide thin film because it has the best higher thermal stability, best resistance against the damage of hydrogen plasma processing and relatively cheaper if one compares it with ITO. Materials and Methods: On glass substrates, Al-doped ZnO (AZO) nanorods have been grown by a low -cost chemical bath deposition (CBD) method at low temperature. The seed layer of ZnO was coated on glass substrates. The effect of the Al-doping on the aligned, surface morphology, density, distribution, orientation and structure of ZnO nanorods are investigated. The Al-doping ratios are 0%, 0.2%, 0.8% and 2%. The Aluminum Nitrate Nonahydrate (Al (NO3)3.9H2O) was added to the growth solution, which is used as a source of the aluminum dopant element. The morphology and structure of the Al-doped ZnO nanorods are characterized by field emission scanning electron microscopy (FESEM) and high-resolution X-ray diffractometer (XRD). using the radio RF (Radio frequency) magnetron technique. Results and Discussion: The results show that the Al-doping have remarkable effects on the topography parameters such as diameter, distribution, alignment, density and nanostructure shape of the ZnO nanorods. These topography parameters have proportionally effective with increases of the Al-doping ratio. Also, X-ray diffraction results show that the Al-doping ratio has a good playing role on the nanostructure orientation of the ZnO nanorods. Conclusions: The Aluminum Nitride Nanohydrate considered as a good Aluminum source for doping ZnONR.  It is clear from FESEM results that the Al-doping of ZnONR has a remarkable effect on the surface topography of nanorods for all aluminum doping ratios. From XRD patterns, it concludes that as the Al-doping ratio increases, the reorientation of the nanostructure of ZnO increases towards [100] direction. The results obtained also have shown that the average diameter of a nanorod is increased with increasing the ratio of Al-doping.

Suppression of defect level emissions in low temperature fabricated one-dimensional Mn doped ZnO nanorods

2013 ◽  
Vol 24 (8) ◽  
pp. 2989-2994 ◽  
Author(s):  
G. Mohan Kumar ◽  
P. Ilanchezhiyan ◽  
Jin Kawakita ◽  
Jinsub Park ◽  
R. Jayavel
Keyword(s):  
Low Temperature ◽  
Zno Nanorods ◽  
Defect Level ◽  
One Dimensional ◽  
Doped Zno ◽  
Mn Doped

scholarly journals Microwave Irradiation to Produce High Performance Thermoelectric Material Based on Al Doped ZnO Nanostructures

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 610
Author(s):  
Neazar Baghdadi ◽  
Numan Salah ◽  
Ahmed Alshahrie ◽  
Kunihito Koumoto
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Microwave Irradiation ◽  
High Performance ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Zno Nanostructures ◽  
Al Doping ◽  
Doped Zno ◽  
Te Material

Microwave irradiation is found to be effective to provide highly crystalline nanostructured materials. In this work, this technique has been used to produce highly improved thermoelectric (TE) material based on aluminum (Al) doped zinc oxide (ZnO) nanostructures (NSs). The effect of Al dopant at the concentration range 0.5–3 mol % on the structural and TE properties has been investigated in more details. The optimum concentration of Al for better TE performance is found to be 2 mol %, which could significantly increase the electrical conductivity and reduce the thermal conductivity of ZnO NSs and thus enhance the TE performance. This concentration showed almost metallic conductivity behavior for ZnO NSs at low temperatures, e.g., below 500 K. The electrical conductivity reached 400 S/m at room temperature, which is around 200 times greater than the value recorded for the pure ZnO NSs. Remarkably, the measured room temperature thermal conductivity of the microwave synthesized ZnO NSs was very low, which is around 4 W/m·K. This value was further reduced to 0.5 W/m·K by increasing the Al doping to 3 mol %. The figure of merit recorded 0.028 at 675 K, which is 15 times higher than that of the pure ZnO NSs. The output power of a single leg module made of 2 mol % Al doped ZnO NSs was 3.7 µW at 485 K, which is higher by 8 times than that of the pure sample. These results demonstrated the advantage of the microwave irradiation rout as a superior synthetic technique for producing and doping promising TE nanomaterials like ZnO NSs.

Effect of Al Excess on the Band Structure of ZnO Using Density Functional Theory

2016 ◽  
Vol 857 ◽  
pp. 106-110
Author(s):  
J.H. Lim ◽  
Cheow Keat Yeoh ◽  
Abdullah Chik ◽  
Pei Leng Teh
Keyword(s):  
Electrical Conductivity ◽  
Density Functional Theory ◽  
Band Structure ◽  
Band Gap ◽  
Density Functional ◽  
Band Structure Calculation ◽  
Al Doping ◽  
Electronic Band ◽  
Functional Theory ◽  
Doped Zno

The effect of Al doping to the band structure of ZnO was studied in this paper. The electronic band structure of Al doped ZnO was determined by using first-principles based on density functional theory. ABINIT was used to perform the band structure calculation. The calculated band structure of ZnO and Al doped ZnO shows that ZnO is a direct band gap semiconductor. The band structure become narrow with Al doping compared pure ZnO. With Al doping, the band gap of ZnO (0.749 eV) become smaller as the concentration Al doping increased to 4wt% (0.551 eV). The electrical conductivity of Al doped ZnO was studied as a references value for the band gap. The electrical conductivity of ZnO (8.21 S/cm) was enhanced with Al doping increased to 4wt% (71.87 S/cm).

Thermoelectric Properties of Al Doped ZnO Thin Films Fabricated through Inkjet Printing

2019 ◽  
Vol 298 ◽  
pp. 214-219 ◽  
Author(s):  
J.H. Lim
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Thermoelectric Properties ◽  
Zno Thin Films ◽  
Al Doping ◽  
Wurtzite Phase ◽  
Ink Jet Printing ◽  
Ink Jet ◽  
Jet Printing ◽  
Doped Zno

The effects of Al doping to the thermoelectric properties of ZnO thin films fabricated through ink-jet printing were studied in this paper. Ink-jet printing was used to deposit the Al doped ZnO thin films. A minimum of 50 print cycles was required to obtain continuous film with approximately 9 μm thick thin films. It was possible to obtain high thermoelectric properties of ZnO by controlling the ratios of dopant added and the temperature of the heat treatments.The XRD traces of Al doped ZnO exhibit a polycrystalline hexagonal structure for the wurtzite phase of ZnO. There were no additional phase detected for Al doped ZnO thin films with increasing amount of Al dopants and heat treatment temperature. The results show Al doping had improved the thermoelectric properties of ZnO with an increased in electrical conductivity. The electrical conductivity of pure ZnO thin film (5 S/cm) was enhanced with increasing the dopant to 4wt% Al doped ZnO (114 S/cm). Negative Seebeck values were observed for all the samples that indicated n-type semiconductor. Pure ZnO samples have a measured Seebeck coefficient-17.63 μV/K decreased to-14.35 μV/K with 4 wt% Al doped.

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