Additional Phonon Modes related to intrinsic defects in CdHgTe
|Jacek Polit 1, E Sheregii 1, A Kisiel 2, B V. Robouch 3, M Cestelli Guidi 4, J Cebulski 1, Andrzej Mycielski 5, M Piccinini 3|
1. University of Rzeszow, Institute of Physics, Rejtana 16, Rzeszów 35-310, Poland
Data of the optical reflectivity measurements obtained in far and middle infrared regions for 11 sample of CdxHg1-xTe (x=0.06-0.7) in temperature interval from 20 K to 293 K with using of synchrotron radiation (DAFNE- LIGHT in LNF, Italy) as source are presented. The curves of Im e (w) obtained by Kramers-Kroning transformation were analyzed by Lorentzian-approximation of dielectric function using model of deformed tetrahedra. Beside 8 canonical phonon modes observed earlier by Kozyrev et.al. , where the region below 120 cm-1 was excluded from consideration, the additional several lines were observed by us in this region. The same lines were presented in publications of another authors . Our analysis is based on data for samples of different types (n- and p-type) and technology as well as on temperature dependences of the discussed line intensity in region from 70 cm-1 to 118 cm-1. This analyze shown that two kinds of lines are observed in this region: first type – generated by electronic structure; second one – generated by oscillations in defect-bearing tatrahedra. The last one are Additional Phonon Modes observed earlier in CdTe .  Kozyrev et. al. Phys. Rev. B, 58,3,1374(1998), ;  Li Biao, Appl.phys.lett, 73,11,1538,(1998);  Polit J. Shereghii E.M., Cebulski J. et. Al., J. Appl. Phys.100,013521, (2006).
Presentation: Oral at E-MRS Fall Meeting 2008, Symposium J, by Jacek Polit
See On-line Journal of E-MRS Fall Meeting 2008
Submitted: 2008-04-30 13:32 Revised: 2009-06-07 00:48