Atomistic Simulations of Calcium Uranyl(VI) Carbonate Adsorption on Calcite and Stepped-Calcite Surfaces

2012 ◽  
Vol 46 (14) ◽  
pp. 7587-7594 ◽  
Author(s):  
Slimane Doudou ◽  
David J. Vaughan ◽  
Francis R. Livens ◽  
Neil A. Burton
Keyword(s):  
Atomistic Simulations ◽  
Carbonate Adsorption

scholarly journals Dynamic lattice distortions driven by surface trapping in semiconductor nanocrystals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Burak Guzelturk ◽  
Benjamin L. Cotts ◽  
Dipti Jasrasaria ◽  
John P. Philbin ◽  
David A. Hanifi ◽  
...  
Keyword(s):  
Photon Energy ◽  
Semiconductor Nanocrystals ◽  
Atomic Scale ◽  
Atomistic Simulations ◽  
Shell System ◽  
Structural Distortions ◽  
Colloidal Semiconductor Nanocrystals ◽  
Femtosecond Electron Diffraction ◽  
Structural Deformations ◽  
Nonradiative Processes

AbstractNonradiative processes limit optoelectronic functionality of nanocrystals and curb their device performance. Nevertheless, the dynamic structural origins of nonradiative relaxations in such materials are not understood. Here, femtosecond electron diffraction measurements corroborated by atomistic simulations uncover transient lattice deformations accompanying radiationless electronic processes in colloidal semiconductor nanocrystals. Investigation of the excitation energy dependence in a core/shell system shows that hot carriers created by a photon energy considerably larger than the bandgap induce structural distortions at nanocrystal surfaces on few picosecond timescales associated with the localization of trapped holes. On the other hand, carriers created by a photon energy close to the bandgap of the core in the same system result in transient lattice heating that occurs on a much longer 200 picosecond timescale, dominated by an Auger heating mechanism. Elucidation of the structural deformations associated with the surface trapping of hot holes provides atomic-scale insights into the mechanisms deteriorating optoelectronic performance and a pathway towards minimizing these losses in nanocrystal devices.

Sign in / Sign up

Export Citation Format

Share Document