Two color spectroscopy of ZnSe:Cr
|Vitalii Y. Ivanov 1,3, Marek Godlewski 1,2, Tom Gregorkiewicz 3|
1. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland
Chromim doped ZnSe is very promising material for optoelectronics (tunable lasing in Mid Infrared) and spintronics (high temperature ferromagnetism) applications.
In this communications two-color spectroscopy (pulse-to-probe) experiments are discussed. We show that two strong Cr2+ intra-shell emissions, the first at 930-1300 nm (with life time τ=1.8 ms) and the second at about 2200-2800 nm, can be efficiently pumped upon the Cr2+ → Cr+ photoionization transition. The intra-shell emission can be enchanced upon additional illumination with Free Electron Laser (FEL) with photon energy tuned at 0.08-0.14 eV range, as we demonstrate for the 930-1300 nm photoluminescence, for which we first present arguments for the Cr2+-centers relation. Enhancement of th intra-shell emissions we relate to ionization of shallow ZnSe acceptors, followed by capture of free holes by Cr+ ions. Hole capture by Cr+ centers proceeds via excited intra-shell states of Cr2+ ions, and thus is followed by two easily detectable Cr2+ intra-shell emissions, opening a simple method for detection of THz radiation for photon energies above 80 meV.
Presentation: Oral at E-MRS Fall Meeting 2006, Symposium F, by Vitalii Y. Ivanov
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-15 16:58 Revised: 2009-06-07 00:44