scholarly journals Effects of Annealing Environments on the Solution-Grown, Aligned Aluminium-Doped Zinc Oxide Nanorod-Array-Based Ultraviolet Photoconductive Sensor

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Mohamad Hafiz Mamat ◽  
Mohd Izzudin Che Khalin ◽  
Nik Noor Hafizah Nik Mohammad ◽  
Zuraida Khusaimi ◽  
Nor Diyana Md Sin ◽  
...  

We have fabricated metal-semiconductor-metal- (MSM-) type ultraviolet (UV) photoconductive sensors using aluminium- (Al-) doped zinc oxide (ZnO) nanorod arrays that were annealed in different environments: air, oxygen, or a vacuum. The Al-doped ZnO nanorods had an average diameter of 60 nm with a thickness of approximately 600 nm that included the seed layer (with thickness~200 nm). Our results show that the vacuum-annealed nanorod-array-based UV photoconductive sensor has the highest photocurrent value of  2.43  ×  10-4 A. The high photocurrent is due to the high concentration of zinc (Zn) interstitials in the vacuum-annealed nanorod arrays. In contrast, the oxygen-annealing process applied to the Al-doped ZnO nanorod arrays produced highly sensitive UV photoconductive sensors, in which the sensitivity reached 55.6, due to the surface properties of the oxygen-annealed nanorods, which have a higher affinity for oxygen adsorption than the other samples and were thereby capable of reducing the sensor’s dark current. In addition, the sensor fabricated using the oxygen-annealed nanorod arrays had the lowest rise and decay time constants. Our result shows that the annealing environment greatly affects the surface condition and properties of the Al-doped ZnO nanorod arrays, which influences the performance of the UV photoconductive sensors.

2015 ◽  
Vol 773-774 ◽  
pp. 696-700
Author(s):  
Mohamad Hafiz Mamat ◽  
Mohd Firdaus Malek ◽  
N.N. Hafizah ◽  
Nor Diyana Md Sin ◽  
I. Saurdi ◽  
...  

Fabrication and performance of metal-semiconductor-metal (MSM)–type intrinsic zinc oxide-coated, aluminium-doped ZnO nanorod array-based ultraviolet photoconductive sensors were reported and discussed. The Al-doped ZnO nanorod arrays were prepared using sonicated sol-gel immersion method. The coating process of intrinsic ZnO onto Al-doped ZnO nanorod arrays was performed using radio-frequency (RF) magnetron sputtering at different deposition times varying from 0 to 10 min. We observed that responsivity of the sensors decreased with increasing intrinsic ZnO deposition time, decreasing from 4.81 A/W without coating to 1.37 A/W after 10 min of coating. Interestingly, the sensitivity of the sensors improved with intrinsic ZnO coating, having a maximum value of 19.0 after 1 min coating.


2020 ◽  
Vol 20 (6) ◽  
pp. 3512-3518
Author(s):  
Saleh Khan ◽  
Xiao-He Liu ◽  
Xi Jiang ◽  
Qing-Yun Chen

Highly efficient and effective porous ZnO nanorod arrays were fabricated by annealing ZnO nanorod arrays grown on a substrate using a simple hydrothermal method. The annealing had a positive effect on the nanorod morphology, structure and optical properties. The porosity was closely related to the annealing temperature. After heating at 450 °C, pores appeared on the nanorods. It was demonstrated that the porosity could be exploited to improve the visible light absorption of ZnO and reduce the bandgap from 3.11 eV to 2.99 eV. A combination of improved charge separation and transport of the heat-treated ZnO thus led to an increase in the photoelectrochemical properties. At an irradiation intensity of 100 mW/cm−2, the photocurrent density of the porous nanorod array was approximately 1.3 mA cm−2 at 1.2 V versus Ag/AgCl, which was five times higher than that of the ZnO nanorods. These results revealed the synthesis of promising porous ZnO nanorods for photoelectrochemical applications.


2012 ◽  
Vol 518-523 ◽  
pp. 760-763
Author(s):  
Chang Yun Chen ◽  
Quan Zhan Chen ◽  
Mei Shi ◽  
Feng Zhou ◽  
Chun Hua ◽  
...  

Nonstoichiometric Zinc oxide (ZnO) nanorod arrays doped Co or Ni can be easily obtained by calicining soaked ZnO nanorod arrays. More importantly, the nonstoichiometric doped ZnO nanoarrays have more effective antimicrobial than pure ZnO nanoarrays, which means we can obtain a kind of promising new effective functional nanomaterials.


2010 ◽  
Vol 1253 ◽  
Author(s):  
Boqian Yang ◽  
Xiaoyan Peng ◽  
Hongxin Zhang ◽  
Peterxian Feng ◽  
Marc Achermann

AbstractUsing different pressures of nitrogen, N-doped ZnO nanorod arrays of various densities have been synthesized on quartz substrates by pulsed laser deposition techniques. The nanorods grow preferentially perpendicular to the quartz surface. X-ray diffraction patterns revealed some degradation of the crystal structure at elevated nitrogen pressures. High concentrations of nitrogen doping in ZnO nanorods were estimated by X-ray photoelectron spectroscopy. Raman scattering spectra confirmed the wurtzite structure of N-doped ZnO nanorods. A prototype sensor based on the N-doped ZnO nanorod arrays demonstrates a linear dependence of the conductivity with operating temperature and pressure of a test gas pollutant.


2011 ◽  
Vol 418-420 ◽  
pp. 1507-1510
Author(s):  
Chun Mei Zhang ◽  
Tao Meng ◽  
Yan Ping Hao ◽  
Qiang Chen

Well-aligned crystalline ZnO nanorod arrays were synthesized on the glass substrate via an aqueous solution route, and the effect of the pH value on structural properties and morphology of ZnO nanorod arrays was investigated using XRD and FESEM. FESEM micrographs show the formation of ZnO nanorod arrays at different pH values. XRD patterns confirm that the ZnO nanorods were wurtzite structure preferentially oriented in c-axis direction and the highest quality of nanorod array was formed at high pH value.


2007 ◽  
Vol 121-123 ◽  
pp. 809-812
Author(s):  
Ya Lin Lu ◽  
Iyad A. Dajani ◽  
W.J. Mandeville ◽  
R.J. Knize ◽  
S.S. Mao

In this research, nanoscale spatial resolution p-n junction photodetector arrays were developed using ZnO nanorod arrays grown on p-type silicon substrates. In order to optimize the nanorod array quality, an advanced combinatorial spreadsheet approach was used to optimize the Au catalyst thickness. The crystallinity of these as-grown ZnO nanorods’ was compared to that of bulk and thin film ZnO materials.


CrystEngComm ◽  
2017 ◽  
Vol 19 (41) ◽  
pp. 6085-6088 ◽  
Author(s):  
Amany Ali ◽  
DongBo Wang ◽  
JinZhong Wang ◽  
ShuJie Jiao ◽  
FengYun Guo ◽  
...  

The ultraviolet luminescence of ZnO nanorods was greatly enhanced through introducing an AlN buffer layer.


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