2007 ◽  
Author(s):  
M. Steger ◽  
A. Yang ◽  
D. Karaiskaj ◽  
M. L. W. Thewalt ◽  
E. E. Haller ◽  
...  

2019 ◽  
Vol 61 (5) ◽  
pp. 817
Author(s):  
В.И. Соколов ◽  
Н.Б. Груздев ◽  
В.А. Важенин ◽  
А.В. Фокин ◽  
А.В. Дружинин

AbstractThe results of the study of optical absorption and EPR signals of single crystals of zinc oxide doped with manganese are presented. A broad impurity absorption band with the threshold energy about 2.1 eV, which was treated as a result of charge transfer transitions, has been observed for a long time in ZnO : Mn absorption spectra. In absorption spectra of a polarized light at 4.2 and 77.3 K, we first detected several lines of different intensity in a 1.877–1.936 eV range of energies of the light quanta. The observed lines are attributed to a donor exciton [( d ^5 + h ) e ] that emerges as a result of the Coulomb binding a free s electron and a hole, which is localized on p – d hybridized states. The EPR spectra of Mn^2+ ion signals, when corresponding to the impurity absorption band exposed to light, are found to be not photosensitive. The obtained results indicate that the ZnO : Mn impurity absorption is due to transitions from antibonding p – d hybridized DBH states to the conduction band.


Author(s):  
Taras Kavetskyy ◽  
Nataliya Pavlyukh ◽  
Volodymyr Tsmots ◽  
Wei Wang ◽  
Jing Ren ◽  
...  

1969 ◽  
Vol 47 (16) ◽  
pp. 1703-1708 ◽  
Author(s):  
Dennis Dunn

We have investigated theoretically the shape of the long-wavelength edge of the impurity absorption spectrum in an insulator (or semiconductor) by means of a Green's function technique. The absorption process is assumed to be the excitation of a valence electron into a previously unoccupied impurity state. We have shown that Urbach's rule is obeyed, that is the absorption coefficient depends exponentially upon the photon energy, if either the valence electron or the impurity state electron is coupled strongly to monoenergetic phonons.


1996 ◽  
Author(s):  
E. Menéndez ◽  
C. Trallero-Giner ◽  
E. Casado

1993 ◽  
Vol 59 (5-6) ◽  
pp. 884-890
Author(s):  
L. G. Skornyakov ◽  
A. V. Gur'ev ◽  
V. D. Zhuravlev
Keyword(s):  

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