| Dr. Maosheng Miao Senior Research Associate Department of Physics Case Western Reserve University 104A Rockfeller Building 10900 Euclid Ave. Cleveland OH 44106-7079 Tel: (216)3684034 Fax: (216)3684671 Email: miaoms@case.edu |
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RECENT ACTIVITIES
April 6, 2006 Poster at the 2006 Research ShowCASE in Cleveland
March 13-17, 2006 Talk at the 2006 APS March Meeting in Baltimore
Sept. 18-23, 2005 Invited talk at the International Conference on Silicon Carbide and Related Materials 2005 in Pittsburgh
Aug. 1-5, 2005 Talk at the 2005 14th APS Topical Conference on Shock Compression of Condensed Matter in Baltimore, MD
March 21-25, 2005 Talk1 talk2 at the 2005 APS March Meeting in Los Angeles
CURRENT RESEARCH INTERESTS
- Transition metal doped wide gap semiconductors: To study the defect levels and the magnetic properties of 3d transition metals from Ti to Cu doped in wide gap semiconductors such as SiC and GaN. The defect levels change slightly for different polytypes or for different layers in 4H SiC. The calculated defect levels are generally in good agreement with DLTS results. We are developing new methods to improve the accuracy of our calculations, especially for high charged defect states and defects close to the conduction band minimum.
- Magnetic and optical properties of transition metal compounds: To study the electronic, magnetic, and optical properties of transition metal binary and ternary compounds, such as MnN, CrAs, CrSb, MnAs, Mn3GaN et al. One reason to study them is that they form a second phase during the growth of dilute magnetic semiconductors. On the other hand, they can by themselves be very useful in spintronics devices due to their magnetic and optical properties
- Stacking faults and quantum well in SiC polytypes: The band gaps of SiC polytypes vary by about 1 eV. They can form various quantum well and superlattice structures. We have studied systems such as single and double stacking faults and 3C inclusions in 4H SiC. Currently, we are studying the features of 8H inclusions in 4H SiC.
- Kinetic study of high pressure phase transitions: We are studying the transition paths between various crystallographic phases and the effects of anisotropic strain. We have found a unified path in the phase transition between the zincblende and wurtzite to rocksalt structure and found that the transition state geometry is universal for different semiconductor compounds.
- Chalcopyrite semiconductors: Ternary I-III-VI2 and II-IV-V2 compounds such as ZnGeP2 etc. complement existing binary semiconductors to form a larger semiconductor family.We are interested in these materials nonlinear optical properties and their possible use as a host for dilute magnetic semiconductors. We are also interested in the defect properties of these compounds.
REPRESENTATIVE PUBLICATIONS
Universal Transition State for High Pressure Zincblene to Rocksalt Phase Transitions, M.S. Miao and Walter R.L. Lambrecht, Phys. Rev. Lett. 94, 225501 (2005).
Theoretical Study of Cation Related Point Defects in ZnGeP2, Xiaoshu Jiang, M. S. Miao and W. R. L. Lambrecht, Phys. Rev. B 71, 205212 (2005).
Magnetic Properties of Substitutional 3d Transition Metal Impurities in Silicon Carbide, M. S. Miao and W. R. L. Lambrecht, Phys. Rev. B 68, 125204 (2003)
Electronic structure and magnetic interactions in MnN and Mn3N2, W. R. L. Lambrecht, Margarita Prikhodko and M.S. Miao, Phys. Rev. B 68, 174411 (2003).
Unified path for high-pressure transitions of SiC poltypes to rocksalt, M. S. Miao and W. R. L. Lambrecht, Phys. Rev. B 68, 092103 (2003).
Electronic Structure of Thin Heterocrystalline Superlattices in SiC and AlN, M. S. Miao and W. R. L. Lambrecht, Phys. Rev. B 68, 155320 (2003).
Stacking Fault Band Structure in 4H SiC amd Its Impact on Electronic Devices, M. S. Miao, Sukit Limpijumnong and W. R. L. Lambrecht, App. Phys. Lett. 79 (26), 4360 (2001).
Density Functional Derivatives from Exact Orbital Functionals, M. S. Miao, Chem. Phys. Lett. 324, 447 (2000).
Conformational and Electronic Structure of Polyethylene: A Density Functional Approach, M. S. Miao, P. E. Van Camp, V. E. Van Doren, J. J. Ladik and J. W. Mintmire, Phys. Rev. B 54, 10430 (1996).