1. A Codoping Route to Realize Low Resistive and Stable p-Type Conduction in (Li, Ni):ZnO Thin Films Grown by Pulsed Laser Deposition
- Author
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E. Senthil Kumar, Jyotirmoy Chatterjee, N. Rama, M. S. Ramachandra Rao, and Nandita DasGupta
- Subjects
Chemical state ,Materials science ,X-ray photoelectron spectroscopy ,Transition metal ,Electrical resistivity and conductivity ,Analytical chemistry ,General Materials Science ,Nanotechnology ,Activation energy ,Co-doped ,Co-doping ,Electrical resistivity ,Homoepitaxial ,II-VI semiconductor ,Mole percent ,P type ZnO thin film ,P-Type conduction ,Room temperature ,Solubility limits ,Transitional metal ions ,UV illuminations ,XPS measurements ,ZnO ,ZnO films ,Deposition ,Electric conductivity ,Hole concentration ,Manganese ,Metal ions ,Metallic films ,Pulsed laser deposition ,Thin films ,Vapor deposition ,Zinc oxide ,Semiconductor doping ,Conductivity ,Thin film - Abstract
We report on the growth of Li-Ni codoped p-type ZnO thin films using pulsed laser deposition. Two mole percent Li monodoped ZnO film shows highly insulating behavior. However, a spectacular decrease in electrical resistivity, from 3.6 � 10 3 to 0.15 ? cm, is observed by incorporating 2 mol % of Ni in the Lidoped ZnOfilm.Moreover, the activation energy drops to 6meV from78 meV with Ni incorporation in Li:ZnO lattice. The codoped [ZnO:(Li, Ni)] thin film shows p-type conduction with room temperature hole concentration of 3.2 � 10 17 cm -3. Photo-Hall measurements show that the Li-Ni codoped p-ZnOfilm is highly stable even with UV illumination. XPS measurements reveal that most favorable chemical state of Ni is Ni 3+ in (Li, Ni): ZnO. We argue that these Ni 3+ ions act as reactive donors and increase the Li solubility limit. Codoping of Li, with other transitional metal ions (Mn, Co, etc.) in place of Ni could be the key to realize hole-dominated conductivity in ZnO to envisage ZnO-based homoepitaxial devices. � 2011 American Chemical Society.
- Published
- 2011
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