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Faculty Publications

Phonons

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Large And Realistic Models Of Amorphous Silicon, Dale Ingram, Bishal Bhattarai, Parthapratim Biswas, David A. Drabold Jul 2018

Large And Realistic Models Of Amorphous Silicon, Dale Ingram, Bishal Bhattarai, Parthapratim Biswas, David A. Drabold

Faculty Publications

Amorphous silicon (a-Si) models are analyzed for structural, electronic and vibrational characteristics. Several models of various sizes have been computationally fabricated for this analysis. It is shown that a recently developed structural modeling algorithm known as force-enhanced atomic refinement (FEAR) provides results in agreement with experimental neutron and X-ray diffraction data while producing a total energy below conventional schemes. We also show that a large model (∼ 500 atoms) and a complete basis is necessary to properly describe vibrational and thermal properties. We compute the density for a-Si, and compare with experimental results.

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Temperature-Dependent Photoluminescence Of Ge/Si And Ge 1-Ysn Y/Si, Indicating Possible Indirect-To-Direct Bandgap Transition At Lower Sn Content, Mee-Yi Ryu, Thomas R. Harris, Yung Kee Yeo, Richard T. Beeler, John Kouvetakis May 2013

Temperature-Dependent Photoluminescence Of Ge/Si And Ge 1-Ysn Y/Si, Indicating Possible Indirect-To-Direct Bandgap Transition At Lower Sn Content, Mee-Yi Ryu, Thomas R. Harris, Yung Kee Yeo, Richard T. Beeler, John Kouvetakis

Faculty Publications

Temperature (T)-dependent photoluminescence (PL) has been investigated for both p-Ge and n-Ge1-ySny films grown on Si substrates. For the p-Ge, strong direct bandgap (ED) along with weak indirect bandgap related (EID) PL at low temperatures (LTs) and strong ED PL at room temperature (RT) were observed. In contrast, for the n-Ge1-ySny, very strong dominant EID PL at LT and strong ED PL were observed at RT. This T-dependent PL study indicates that the indirect-to-direct bandgap transitions of Ge1-ySn …

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Erratum: “Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal” [Appl. Phys. Lett.87, 182104 (2005)], B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal Apr 2006

Erratum: “Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal” [Appl. Phys. Lett.87, 182104 (2005)], B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal

Faculty Publications

No abstract provided.

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Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal, B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal Oct 2005

Terahertz Studies Of The Dielectric Response And Second-Order Phonons In A Gase Crystal, B. L. Yu, F. Zeng, V. Kartazayev, R. R. Alfano, K. C. Mandal

Faculty Publications

No abstract provided.

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Tb3+-Doped K Pb2Br5: Low-Energy Phonon Mid-Infrared Laser Crystal, U. N. Roy, R. H. Hawrami, Y. Cui, S. Morgan, A. Burger, K. C. Mandal, C. C. Noblitt, S. A. Speakman, K. Rademaker, S. A. Payne Apr 2005

Tb3+-Doped K Pb2Br5: Low-Energy Phonon Mid-Infrared Laser Crystal, U. N. Roy, R. H. Hawrami, Y. Cui, S. Morgan, A. Burger, K. C. Mandal, C. C. Noblitt, S. A. Speakman, K. Rademaker, S. A. Payne

Faculty Publications

No abstract provided.

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Observation Of An Oxygen Isotope Effect In Yba2Cu3O7, Kevin J. Leary, Hans Conrad Zur Loye, Steven W. Keller, Tanya A. Faltens, William K. Ham, James N. Michaels, Angelica M. Stacy Sep 1987

Observation Of An Oxygen Isotope Effect In Yba2Cu3O7, Kevin J. Leary, Hans Conrad Zur Loye, Steven W. Keller, Tanya A. Faltens, William K. Ham, James N. Michaels, Angelica M. Stacy

Faculty Publications

A small decrease in Tc of 0.3 K to 0.5 K is observed when as much as 90% of the 16O in YBa2Cu3O7 is substituted with18O. This result is consistent with our observation that there is an oxygen isotope effect in La1.85Sr0.15CuO4, but in contrast with previous reports that there is no isotope effect for YBa2Cu3O7. This new result suggests that phonons play an important role in the electron-pairing mechanism in YBa2Cu3O7.

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