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Au-Ge bonding on uniformly Au-covered Ge(001) surface

  1. Top of page
  2. Au-Ge bonding on uniformly Au-covered Ge(001) surface
  3. MOF-FF - A flexible first-principles-derived force field for metal-organic frameworks
  4. Advantages of blue InGaN light-emitting di-odes with composition-graded barriers and electron-blocking layer

Dana G. Popescu and Marius A. Husanu

In the context of recently emerging Au/Ge(001) one-dimensional systems, the authors investigate the chemical bonding of one monolayer Au deposited on a dimerized Ge(001) surface. Effects on the covalent bonding of Au on the Ge dimer surface are shown combining photoelectron spectroscopy with first-principles calcu-lations.

Phys. Status Solidi RRL (2013) DOI 10.1002/pssr.201307029

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MOF-FF - A flexible first-principles-derived force field for metal-organic frameworks

  1. Top of page
  2. Au-Ge bonding on uniformly Au-covered Ge(001) surface
  3. MOF-FF - A flexible first-principles-derived force field for metal-organic frameworks
  4. Advantages of blue InGaN light-emitting di-odes with composition-graded barriers and electron-blocking layer

Sareeya Bureekaew, Saeed Amirjalayer, Maxim Tafipolsky, Christian Spickermann, Tapta Kanchan Roy, and Rochus Schmid

The development, definition and selected applications of a new force field for metal-organic frameworks MOF-FF are presented here. MOF-FF is fully flexible and is parameterized in a systematic and consistent fashion from first principles reference data. It can be used for a variety of different MOF-families and in particular - due to the reparametrization of a variety of organic linkers - also to explore isoreticular series of systems. The history of the development, leading to the final definition of MOF-FF is re-viewed along with the application of the previous incarnations of the force field. In addition, the parametrization approach is ex-plained in a tutorial fashion. The currently parametrized set of inorganic building blocks is constantly extended.

Phys. Status Solidi B (2013) DOI 10.1002/pssb.201248460

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Advantages of blue InGaN light-emitting di-odes with composition-graded barriers and electron-blocking layer

  1. Top of page
  2. Au-Ge bonding on uniformly Au-covered Ge(001) surface
  3. MOF-FF - A flexible first-principles-derived force field for metal-organic frameworks
  4. Advantages of blue InGaN light-emitting di-odes with composition-graded barriers and electron-blocking layer

Jih-Yuan Chang and Yen-Kuang Kuo

Numerical investigation on the influences of graded barriers and graded electron-blocking layer (EBL) in blue InGaN light-emitting diodes (LEDs) is presented by Chang and Kuo. When both the graded barriers and graded EBL are employed simultaneously, the LED structures benefit from both superior hole-injection efficiency and enhanced carrier transportation in the active region. The carrier distribution among the quantum wells becomes more uniform, which results in an improved radiative recombination rate and reduced Auger recombination. If the grading scheme of indium composition in the barriers is well designed, an optimal situation can be obtained. For the optimal structure in this study (In: 0∼9%), the output power at 222 A/cm2 is increased by 30% when compared to the original structure.

Phys. Status Solidi A (2013) DOI 10.1002/pssa.201228764

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