Wang, L. G. and Xiong, Y. and Xiao, W. and Cheng, L. and Du, J. and Tu, H. and van de Walle, A. (2014) Computational investigation of the phase stability and the electronic properties for Gd-doped HfO_2. Applied Physics Letters, 104 (20). Art. No. 201903. ISSN 0003-6951. http://resolver.caltech.edu/CaltechAUTHORS:20140703-102724197
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Abstract
Rare earth doping is an important approach to improve the desired properties of high-k gate dielectric oxides. We have carried out a comprehensive theoretical investigation on the phase stability, band gap, formation of oxygen vacancies, and dielectric properties for the Gd-doped HfO_2. Our calculated results indicate that the tetragonal phase is more stable than the monoclinic phase when the Gd doping concentration is greater than 15.5%, which is in a good agreement with the experimental observations. The dopant's geometric effect is mainly responsible for the phase stability. The Gd doping enlarges the band gap of the material. The dielectric constant for the Gd-doped HfO_2 is in the range of 20–30 that is suitable for high-k dielectric applications. The neutral oxygen vacancy formation energy is 3.2 eV lower in the doped material than in pure HfO_2. We explain the experimental observation on the decrease of photoluminescence intensities in the Gd-doped HfO_2 according to forming the dopant-oxygen vacancy complexes.
| Item Type: | Article | |||||||||
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| Alternate Title: | Computational investigation of the phase stability and the electronic properties for Gd-doped HfO2 | |||||||||
| Additional Information: | © 2014 American Institute of Physics Publishing LLC. Received 20 January 2014; accepted 6 May 2014; published online 20 May 2014. The authors wish to thank Dr. Jürgen Furthmüller for useful discussions on the dielectric constant calculations. Y.X., J.D., and H.L.T. are partially supported by the NSF of China (Contract No. 50932001). | |||||||||
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| Record Number: | CaltechAUTHORS:20140703-102724197 | |||||||||
| Persistent URL: | http://resolver.caltech.edu/CaltechAUTHORS:20140703-102724197 | |||||||||
| Official Citation: | Computational investigation of the phase stability and the electronic properties for Gd-doped HfO2 L. G. Wang, Y. Xiong, W. Xiao, L. Cheng, J. Du, H. Tu and A. van de Walle Appl. Phys. Lett. 104, 201903 (2014); http://dx.doi.org/10.1063/1.4878401 | |||||||||
| Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. | |||||||||
| ID Code: | 46807 | |||||||||
| Collection: | CaltechAUTHORS | |||||||||
| Deposited By: | Ruth Sustaita | |||||||||
| Deposited On: | 03 Jul 2014 18:11 | |||||||||
| Last Modified: | 03 Jul 2014 23:39 |
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