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Full-Text Articles in Physics
Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton
Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton
Faculty Publications
Electron paramagnetic resonance (EPR) is used to identify a new and unique photoactive silicon-related point defect in single crystals of rutile TiO2. The importance of this defect lies in its assignment to interstitial silicon ions and the unexpected establishment of silicon impurities as a major hole trap in TiO2. Principal g values of this new S=1/2 center are 1.9159, 1.9377, and 1.9668 with principal axes along the [¯110],[001], and [110] directions, respectively. Hyperfine structure in the EPR spectrum shows the unpaired spin interacting equally with two Ti nuclei and unequally with two Si nuclei. These silicon …
Theoretical Investigation Of Stabilities And Optical Properties Of Si12C12 Clusters, Xiaofeng F. Duan, Larry W. Burggraf
Theoretical Investigation Of Stabilities And Optical Properties Of Si12C12 Clusters, Xiaofeng F. Duan, Larry W. Burggraf
Faculty Publications
By sorting through hundreds of globally stable Si12C12 isomers using a potential surface search and using simulated annealing, we have identified low-energy structures. Unlike isomers knit together by Si–C bonds, the lowest energy isomers have segregated carbon and silicon regions that maximize stronger C–C bonding. Positing that charge separation between the carbon and silicon regions would produce interesting optical absorption in these cluster molecules, we used time-dependent density functional theory to compare the calculated optical properties of four isomers representing structural classes having different types of silicon and carbon segregation regions. Absorptions involving charge transfer between segregated …
Monolithic Optofluidic Ring Resonator Lasers Created By Femtosecond Laser Nanofabrication, Hengky Chandrahalim, Qiushu Chen, Ali A. Said, Mark Dugan, Xudong Fan
Monolithic Optofluidic Ring Resonator Lasers Created By Femtosecond Laser Nanofabrication, Hengky Chandrahalim, Qiushu Chen, Ali A. Said, Mark Dugan, Xudong Fan
Faculty Publications
We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ/mm2. Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3 × 104, which is limited by both solvent …