Search for content and authors

Photo-EPR studies of charge tunneling processes in CdxZn(1-x)Se:Fe,Cr (0 ≤ x ≤ 0.3) crystals

Krzysztof Swiatek 1Marek Godlewski 1,2Tanya Surkova 3

1. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland
2. Cardinal Stefan Wyszynski University, College of Science, Deptartment of Mathematics and Natural Sciences, Warszawa, Poland
3. Russian Academy of Sciences, Ural Division, Institute of Metal Physics, 18 S.Kovalevskaya str., GSP-170, Ekaterinburg 620219, Russian Federation


Mechanisms by which localized excitations move through a crystal are of great interest in various fields of solid state physics. Such kind of transfer takes place in, e.g., laser, cathodoluminescent and electroluminescent materials.
In this communication we analyze tunneling processes of photo - generated electrons and holes between impurities in CdxZn(1-x)Se:Fe,Cr (x = 0, 0.1, 0.2, 0.3) bulk crystals. To study migration of electrons among donor, iron, chromium, and acceptor after switching off external illumination, changes of electron paramagnetic resonance (EPR) signals of the Fe3+ and Cr1+ ions were detected. Measured decay times of the EPR signals at liquid helium temperature were long (τd ~ 103 s). However, decay of the Fe3+ signal was a bit faster than decay of the Cr1+ signal. Increase of temperature caused decrease of the measured decay times for both impurities. Observed temperature dependence of τd has so called activation character. Energy value determined from such dependence correlates well with thermal ionization energy of donors present in the CdZnSe:Fe,Cr system. Results are compared with previous data of Zakrzewski and Godlewski obtained for ZnS:Cu,Fe,Cr.


Legal notice
  • Legal notice:

Related papers

Presentation: Poster at E-MRS Fall Meeting 2006, Symposium F, by Marek Godlewski
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-05-15 20:47
Revised:   2009-06-07 00:44