Optical properties of thePb2+-based aggregated phase in a CsCl host crystal: Quantum-confinement effects

1995 ◽  
Vol 51 (8) ◽  
pp. 5192-5199 ◽  
Author(s):  
M. Nikl ◽  
K. Nitsch ◽  
K. Polak ◽  
G. P. Pazzi ◽  
P. Fabeni ◽  
...  
2001 ◽  
Vol 15 (02) ◽  
pp. 191-200 ◽  
Author(s):  
M. GHANASHYAM KRISHNA ◽  
A. K. BHATTACHARYA

Quantum confinement effects on the optical properties of ion beam sputtered nickel oxide thin films are reported. Thin films with crystallite sizes in the range 9 to 14 nm have been deposited on to fused silica substrates. There is an increase in band gap, from 3.4 to 3.9 eV, and a decrease in refractive index, from 2.4 to 1.6, with decrease in crystallite size, that can be attributed to quantum confinement effects. The effective mass approximation has been used to explain the observed behaviour in band gap variation.


2012 ◽  
Vol 725 ◽  
pp. 251-254
Author(s):  
Yuki Mizukami ◽  
D. Kosemura ◽  
M. Takei ◽  
Y. Numasawa ◽  
Y. Ohshita ◽  
...  

Raman spectroscopy and photoluminescence were performed in order to understand the optical properties of nanocrystal Si in relation to quantum confinement effects. The nanocrystal Si (nc-Si) dots in the SiO2 layer were fabricated by the H2 plasma treatment and chemical vapour deposition followed by the oxidation of the nc-Si dots surface. The post-annealing was also performed to improve the crystalline quality of nc-Si at 1050 °C for 5 and 10 min. There is a good correlation of the quantum confinement effects between the results of Raman spectroscopy and photoluminescence. The Raman spectra from nc-Si were analysed using the model of Richter et al. As a result, the sizes of the nc-Si dots were consistent with those obtained by transmission electron microscopy and X-ray diffraction. Moreover, the compressive stress in the nc-Si dots were evaluated which was induced by the SiO2 surroundings.


2015 ◽  
Vol 17 (7) ◽  
pp. 5063-5071 ◽  
Author(s):  
Debajyoti Das ◽  
Arup Samanta

An energy blue shift due to quantum confinement effects in tiny nc-Si QDs accompanied by larger Stokes shifts in PL at smaller dimensions.


2011 ◽  
Vol 675-677 ◽  
pp. 243-246 ◽  
Author(s):  
Mei Li Guo ◽  
Xiao Dong Zhang

ZnO nanowires are promising for photonic devices, biosensor and cancer cell imaging. We have performed a first-principles study to evaluate the electronic and optical properties of ZnO nanowires. We have employed the Perdew–Burke–Ernzerhof form of generalized gradient approximation in the frame work of density functional theory. Calculations have been carried out at different configurations. With decreasing diameter, the band gap of ZnO nanowires is increased due to the increase of quantum confinement effects. The results of imaginary part of the dielectric function indicate that the optical transition between valence band and conduction band has shifted to the high energy range as the diameter decreases. The ZnO nanowires show size-tunable optical properties.


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