Radiative properties of α-ZnAl2S4:V spinel type single crystals

On the excitation spectra of Cr3+/Cr2+ and V3+ co-doped ZnAl2S4 single crystals

“…1, both the V 3+ emission around 0.9eV and Cr 3+ emission around 1.6eV have the same spectral position and shape, as was previously reported for each of them separately, in Refs. [10] and [4], respectively. However, there is an additional broad band centered at 1.9eV, which is due to the optical transitions of Cr 2+ ions, as we prove below.…”

“…So, intensive experiments are needed to optimize the characteristics and parameters of the ZnAl 2 S 4 :Cr,V system, which will be the subject for our further studies. [4]. The room temperature excitation spectrum was monitored at 1.9eV emission and the low temperature excitation spectrum was monitored at 2.1eV emission.…”

“…One interesting feature of vanadium ions in this crystal is that some peaks in the emission spectrum are due to the transitions between different excited levels (denoted as the PL1 in Fig.8), which is more typical for the lanthanides rather than for the transition metals ions. At room temperature the emission is due to the 3 T 2g ( 3 F) to 3 [4]. The intensity at room temperature is increased by a factor of four compared to low temperatures (see the Inset).…”

“…[4] and the theoretical calculation on the V 3+ level location within the band gap of the host material was carried out in [3]. Although the reader can find a more detailed description in the above mentioned references, we will present here a short summary of those two publications in order to emphasize what we want do describe further.…”

“…Synthetic α-ZnAl 2 S 4 single crystals doped with various transition metal ions such as Ti, Cr, Co or V have been the subject of investigations in our group in the past few years [1][2][3][4][5] due to their potential applications as optically active media for tunable laser systems. Unlike the crystals containing trivalent chromium, materials with other transition metal ions, especially in other oxidation states, are not easy to deal with.…”