Photoluminescence properties of Cr2+:ZnSe films deposited by radio frequency magnetron cosputtering

Abstract

Origin of stress in radio frequency magnetron sputtered zinc oxide thin films J. Appl. Phys. 109, 064905 (2011); 10.1063/1.3552928Aluminum-nitride codoped zinc oxide films prepared using a radio-frequency magnetron cosputtering system Cr 2+ : ZnSe films were grown at room temperature by the radio frequency magnetron cosputtering technique. The structural characterization of the films shows that the corresponding films are well crystallized mainly in the cubic zinc-blende structure with strong ͗111͘ orientations. Using direct ͑1850 nm͒ and indirect ͑visible͒ excitations, photoluminescence experiments in the midinfrared spectral region reveal that Cr is incorporated in the optically active Cr 2+ state, and the shape of the spectra agrees with that reported for bulk materials. This study shows that magnetron cosputtering can provide viable structures for the realization of optically and electrically pumped midinfrared microlasers.

Structural and photoluminescence properties of Cr2+:ZnSe films deposited by radiofrequency magnetron co-sputtering for mid-infrared microlaser applications

“…3(a). As previously mentioned, both spectra exhibit the same large emission band centred at about 2200 nm and attributed to the 5 E → 5 T 2 intrashell transition of Cr 2+ ions, showing that in our film the chromium has been incorporated in the Cr 2+ state [19]. For P rf < 150 W, no PL emission in this wavelength range was observed and for P rf ≥ 150 W the observed PL relative intensity increases with P rf .…”

First‐principles study of the electronic structures and optical properties of Cr2+‐doped ZnSe as a function of impurity concentration

“…. It is believed that Cr 2+ ions substitute for the Zn 2+ host and occupy tetrahedral sites leading to a smaller crystalline field splitting of the free‐ion energy levels . The fivefold degenerate Cr(d) orbitals are split into two groups: doubly degenerate e orbitals ( and ) and triply degenerate t 2 orbitals (d xy , d xz , and d yz ).…”

Luminescence properties of Cr2+:ZnSe: Comparison between a single crystal and a film deposited by RF magnetron co-sputtering

“…2a. As previously mentioned, both spectra exhibit the same large emission band centred at about 2200 nm and attributed to the 5 E-5 T 2 intrashell transition of Cr 2 + ions, showing that in the film the chromium has been incorporated into the Cr 2 + state [15]. Similar results were obtained for Cr 2 + :ZnSe films deposited by molecular beam epitaxy (MBE) (thickness¼1.4 mm, n Cr 2 þ ¼10 18 at cm À 3 ) at 310 1C [13] and by pulsed laser deposition at 510 1C on GaAs, Si or Sapphir substrate (thickness ¼8 mm) [14].…”

“…In the case of Cr 2 + :ZnSe, pulsed [7], continuous wave [8], mode locked [9] and electroluminescence [10,11] operations are yet to be demonstrated at RT in the 2-3 mm region [12]. Research studies of Cr 2 + :ZnSe are not limited to bulk crystals, but also include thin films prepared by molecular beam epitaxy (MBE) [13], pulsed laser ablation [14] and radiofrequency (RF) magnetron sputtering [15,16] techniques for the purpose of fabricating compact laser systems. In this paper, we compare the optical properties of a Cr 2 + :ZnSe film deposited by RF magnetron sputtering with those of a post growth thermal diffusion doped Cr 2 + :ZnSe single crystal.…”