TY - JOUR
T1 - Effect of thermal annealing on the structural, electrical and optical properties of Al-Ni co-doped ZnO thin films prepared using a sol-gel method
AU - Zhang, X. L.
AU - Hui, K. S.
AU - Bin, Feng
AU - Hui, K. N.
AU - Li, Lei
AU - Cho, Y. R.
AU - Mane, Rajaram S.
AU - Zhou, Wei
PY - 2015/1/15
Y1 - 2015/1/15
N2 - Al-Ni co-doped ZnO (NiAl:ZnO) thin films were deposited on glass substrates using a sol-gel method. Based on a previous study, Zn1-xAlxO (AZO; Al/Zn=1.5mol%) thin films optimized with a Ni content of 0.5mol% were annealed at different temperatures from 450 to 600°C in N2/H2 (95/5) forming gas for 1h. The effects of the annealing temperature on the structural, electrical and optical properties were determined. X-ray diffraction showed that NiAl:ZnO thin film annealed at 500°C exhibited the best crystallization quality. XPS revealed the presence of metallic Ni and Ni2O3 states, as well as Ni and Al atoms were successfully doped in NiAl:ZnO films, which did not result in a change in ZnO crystal structure and orientation. Scanning electron microscopy showed that the films were smooth and compact, and the grain size increased with increasing annealing temperature from ~23.8nm to ~34.6nm. According to the Hall Effect measurements, when the temperature reached 500°C, the resistivity of the thin film showed the lowest value of 1.05×10-3 (Ωcm), which is the lowest resistivity reported for NiAl:ZnO films. The UV-Vis transmission spectra showed a high transmittance of more than 80% in the visible light range, and the band gap of the films was increased from 3.30 to 3.55eV. This study showed that the annealing temperature in the forming gas is a vital factor affecting the quality of thin films. In addition, 500°C was found to be the most appropriate annealing temperature for NiAl:ZnO films. This study provides a simple and efficient method for preparing high quality, high transparency and low resistivity NiAl:ZnO films for optoelectronic applications.
AB - Al-Ni co-doped ZnO (NiAl:ZnO) thin films were deposited on glass substrates using a sol-gel method. Based on a previous study, Zn1-xAlxO (AZO; Al/Zn=1.5mol%) thin films optimized with a Ni content of 0.5mol% were annealed at different temperatures from 450 to 600°C in N2/H2 (95/5) forming gas for 1h. The effects of the annealing temperature on the structural, electrical and optical properties were determined. X-ray diffraction showed that NiAl:ZnO thin film annealed at 500°C exhibited the best crystallization quality. XPS revealed the presence of metallic Ni and Ni2O3 states, as well as Ni and Al atoms were successfully doped in NiAl:ZnO films, which did not result in a change in ZnO crystal structure and orientation. Scanning electron microscopy showed that the films were smooth and compact, and the grain size increased with increasing annealing temperature from ~23.8nm to ~34.6nm. According to the Hall Effect measurements, when the temperature reached 500°C, the resistivity of the thin film showed the lowest value of 1.05×10-3 (Ωcm), which is the lowest resistivity reported for NiAl:ZnO films. The UV-Vis transmission spectra showed a high transmittance of more than 80% in the visible light range, and the band gap of the films was increased from 3.30 to 3.55eV. This study showed that the annealing temperature in the forming gas is a vital factor affecting the quality of thin films. In addition, 500°C was found to be the most appropriate annealing temperature for NiAl:ZnO films. This study provides a simple and efficient method for preparing high quality, high transparency and low resistivity NiAl:ZnO films for optoelectronic applications.
KW - Al-Ni co-doped ZnO
KW - Annealing temperature
KW - Forming gas
KW - Sol-gel method
UR - http://www.scopus.com/inward/record.url?scp=84920744221&partnerID=8YFLogxK
U2 - 10.1016/j.surfcoat.2014.11.043
DO - 10.1016/j.surfcoat.2014.11.043
M3 - Article
AN - SCOPUS:84920744221
VL - 261
SP - 149
EP - 155
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
SN - 0257-8972
ER -