Ultrafast Electron Dynamics in Ge Quantum Dots

1999 ◽  
Vol 571 ◽  
Author(s):  
A. Stella ◽  
P. Tognini ◽  
S. De Silvestri ◽  
M. Nisoli ◽  
S. Stagira ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Conduction Band ◽  
Quantum Confinement ◽  
Spectral Feature ◽  
Wavelength Region ◽  
Electron Dynamics ◽  
Quantum Confinement Effects ◽  
Pump And Probe ◽  
Carrier Interaction ◽  
Ge Quantum Dots

ABSTRACTAn analysis of the ultrafast response of Ge quantum dots, with average radii of 4 nm and 16 nm, is reported here. Pump and probe experiments allowed investigation of the wavelength region between 450 and 750 nrm, characterized by the absorption peaks due to the E, and E1+Δ1 interband transitions. Two different time regimes have been identified: a first one (τ ≤ 1 ps) associated with pump-induced conduction band filling in the τ-L direction in the Brillouin zone; a second one (τ up to 100 ps) associated with band gap renormalization caused by the carrier interaction in the conduction band. Quantum confinement effects show up in terms of sizedependent blueshift of the E1+Δ1 spectral feature.

scholarly journals The role of the interface in germanium quantum dots: when not only size matters for quantum confinement effects

Nanoscale ◽  
2015 ◽  
Vol 7 (26) ◽  
pp. 11401-11408 ◽  
Author(s):  
S. Cosentino ◽  
A. M. Mio ◽  
E. G. Barbagiovanni ◽  
R. Raciti ◽  
R. Bahariqushchi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Quantum Confinement ◽  
Confinement Effects ◽  
Quantum Confinement Effects ◽  
Ge Quantum Dots ◽  
Germanium Quantum Dots ◽  
Interface Effects

This work elucidates the interplay between quantum confinement and interface effects in the optical properties of Ge quantum dots, demonstrating that not only size matters at the nanoscale.

Strong quantum-confinement effects in the conduction band of germanium nanocrystals

2004 ◽  
Vol 84 (20) ◽  
pp. 4056-4058 ◽  
Author(s):  
C. Bostedt ◽  
T. van Buuren ◽  
T. M. Willey ◽  
N. Franco ◽  
L. J. Terminello ◽  
...  
Keyword(s):  
Conduction Band ◽  
Quantum Confinement ◽  
Confinement Effects ◽  
Quantum Confinement Effects ◽  
Germanium Nanocrystals

Experimental observation of quantum confinement in the conduction band of PbS quantum dots

2013 ◽  
Vol 42 (4) ◽  
pp. 197-200 ◽  
Author(s):  
I. N. Demchenko ◽  
M. Chernyshova ◽  
X. He ◽  
R. Minikayev ◽  
Y. Syryanyy ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Experimental Observation ◽  
Conduction Band ◽  
Quantum Confinement ◽  
Pbs Quantum Dots

STUDY OF ELECTRONIC STRUCTURE AND NEGATIVE ELECTRON AFFINITY OF NANODIAMONDS PASSIVATED BY CHn SPECIES

2010 ◽  
Vol 09 (01) ◽  
pp. 353-363
Author(s):  
ZHENKUI ZHANG ◽  
YING DAI
Keyword(s):  
Electron Affinity ◽  
Quantum Confinement ◽  
Density Functional ◽  
Spectral Feature ◽  
Negative Electron Affinity ◽  
Diamond Nanoparticles ◽  
Quantum Confinement Effects ◽  
Homo And Lumo ◽  
Bulk Diamond ◽  
X Ray Absorption

A series of diamond nanoparticles with different surface terminations, (I) CH n (n = 1, 2) and (II) CH n (n = 1–3) species, have been investigated by means of density functional theory (DFT) to probe the effects of the terminated CH n species on the geometric and electronic structures and related properties. Our results show that quantum confinement effects of HOMO–LUMO gap occurs for the series I particles with size up to 1.1 nm, in contrast to the much weaker decay of the gap for larger size. With the existence of additional CH3 species, for size larger than 1 nm, the series II particles have larger gaps than the series I counterparts, which may be even larger than that of bulk diamond. The compositions of HOMO and LUMO are responsible for the different behaviors in the quantum confinement, which agrees with the experimentally observed spectral feature in the X-ray absorption measurement. In addition, our results show that the negative electron affinity is strongly dependent on the C/H ratio for the hydrogenated diamond nanoparticles.

scholarly journals Quantum confinement effects in Si/Ge heterostructures with spatially ordered arrays of self-assembled quantum dots

2010 ◽  
Vol 96 (22) ◽  
pp. 222107 ◽  
Author(s):  
Oleksiy B. Agafonov ◽  
Christian Dais ◽  
Detlev Grützmacher ◽  
Rolf J. Haug
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement ◽  
Confinement Effects ◽  
Ordered Arrays ◽  
Quantum Confinement Effects ◽  
Self Assembled

Quantum confinement effects on the optical phonons of CdTe quantum dots

1998 ◽  
Vol 23 (5) ◽  
pp. 1103-1106 ◽  
Author(s):  
A.M. de Paula ◽  
L.C. Barbosa ◽  
C.H.B. Cruz ◽  
O.L. Alves ◽  
J.A. Sanjurjo ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement ◽  
Cdte Quantum Dots ◽  
Optical Phonons ◽  
Confinement Effects ◽  
Quantum Confinement Effects
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