TY - JOUR
T1 - Growth behaviors and characteristics of low temperature spin-sprayed ZnO and Al-doped ZnO microstructures
AU - Obi, Ogheneyunume
AU - Zhou, Ziyao
AU - Beghun, Shawn
AU - Nan, Tianxiang
AU - Stoute, Stephen
AU - Liu, Ming
AU - Lou, Jing
AU - Yang, Xi
AU - Gao, Yuan
AU - Li, Ming
AU - Xing, Xing
AU - Sun, Nian X.
AU - Warzywoda, Juliusz
AU - Sacco, Albert
AU - Guo, Ting
AU - Nan, Cewen
N1 - Funding Information:
Acknowledgments This work is financially supported by NSF awards 0824008 and by the United States Air Force under contract number FA8721-05-C-0002. The authors would like to thank Prof. V. G. Harris for allowing unlimited access to his XRD equipment, Prof. Ziemer and Dr. B. Sun for XPS measurements and Prof. Cewen Nan in Tsinghua university for measuring optical photoluminescence spectrum in his group.
PY - 2013/6
Y1 - 2013/6
N2 - The influence of growth parameters of the spin-spray technique upon the microstructure and electrical and optical properties of ZnO and Al-doped ZnO microstructures was investigated. This investigation was carried out by varying the pH and concentration of the solutions utilized. With increasing pH from 9 to 12, the ZnO films changed from membrane-like microstructures at a pH of 9 to single crystal ZnO rods with hexagonal ends at the pH of 10, and to polycrystal ZnO needle-like tips with random crystalline orientation at the pH of 12. Varying the concentration of the solution brought about a dramatic change in the crystal growth behavior and crystalline orientation, with the least concentration producing rods more uniform and oriented in the c-axis direction. The optical absorption dependence of the ZnO microstructures was also studied by ultraviolet visible spectrophotometer. This investigation will enable optimized low temperature (<100 C) fabrication of ZnO films by the spin-spray technique with controllable microstructure and properties based on their processing conditions. Furthermore, the influence of Al doping on the electric property, optical property microstructures of the Al-doped ZnO thin films was examined. Increase in Al concentration from 0 to 2 % further reduced the resistivity of the ZnO films by 3 orders of magnitudes from 3.4 × 10 4 to 14 Ω cm; while the Hall mobility increases from 1 to 140 cm2/V s at the same time. The optical photoluminescence measurement of Al-doped ZnO thin films in ultra violet (UV) was also demonstrated.
AB - The influence of growth parameters of the spin-spray technique upon the microstructure and electrical and optical properties of ZnO and Al-doped ZnO microstructures was investigated. This investigation was carried out by varying the pH and concentration of the solutions utilized. With increasing pH from 9 to 12, the ZnO films changed from membrane-like microstructures at a pH of 9 to single crystal ZnO rods with hexagonal ends at the pH of 10, and to polycrystal ZnO needle-like tips with random crystalline orientation at the pH of 12. Varying the concentration of the solution brought about a dramatic change in the crystal growth behavior and crystalline orientation, with the least concentration producing rods more uniform and oriented in the c-axis direction. The optical absorption dependence of the ZnO microstructures was also studied by ultraviolet visible spectrophotometer. This investigation will enable optimized low temperature (<100 C) fabrication of ZnO films by the spin-spray technique with controllable microstructure and properties based on their processing conditions. Furthermore, the influence of Al doping on the electric property, optical property microstructures of the Al-doped ZnO thin films was examined. Increase in Al concentration from 0 to 2 % further reduced the resistivity of the ZnO films by 3 orders of magnitudes from 3.4 × 10 4 to 14 Ω cm; while the Hall mobility increases from 1 to 140 cm2/V s at the same time. The optical photoluminescence measurement of Al-doped ZnO thin films in ultra violet (UV) was also demonstrated.
UR - http://www.scopus.com/inward/record.url?scp=84878725495&partnerID=8YFLogxK
U2 - 10.1007/s10854-012-1056-3
DO - 10.1007/s10854-012-1056-3
M3 - Article
AN - SCOPUS:84878725495
SN - 0957-4522
VL - 24
SP - 2058
EP - 2066
JO - Journal of Materials Science: Materials in Electronics
JF - Journal of Materials Science: Materials in Electronics
IS - 6
ER -