Phase diagram of the CdGa2Se4−Bi2Se3 system and growth of CdGa2Se4 single crystals

Electronic structure of cadmium selenogallate CdGa2Se4 as studied using ab initio calculations and X-ray photoelectron spectroscopy

“…The slow cooling process was carried out up to room temperature with a rate of 5 K h −1 . The crystal used for the present experimental study was a single-phase orange material with the energy gap of 2.35 ± 0.05 eV as estimated from the absorption edge measured at 298 K [20]. The above value of the energy gap corresponds well to that (2.33 eV) obtained by Kim et al [29] for a CdGa2Se4 single crystal.…”

“…[34]. This fact can be explained by a bigger value of the energy gap, E g , of CdGa 2 S 4 (E g ≈ 3.50 eV [30]) as compared with that of CdGa 2 Se 4 (from 2.33 to 2.57 eV [12,20,[29][30][31]). …”

“…[20]. Briefly, a CdGa2Se4 crystal studied in the present work was grown by the solution-melt method when investigating the phase diagram of the CdGa2Se4-Bi2Se3 system [20], with an optimum solvent concentration of 45 mol.% Bi2Se3. The initial elements, used for synthesis of the CdGa2Se4 crystal, were of purity better than 99.99 wt.%.…”

“…Therefore, different routes are applied for obtaining high-quality bulk crystals of CdGa 2 Se 4 , e.g. chemical vapour transport (CVT) reactions in which iodine is used as a transport agent [14][15][16], chemical vapour deposition (CVD) [17], the flux and solution-melt methods [18][19][20].…”

The CdSe–Ga2Se3–PbSe system

“…Unfortunately, the formation of significant solid solutions up to several mol.% of the ternary phase was observed in all cases. More interesting is the use of Bi 2 Se 3 [6] or PbSe [7]. Large ionic radii of Bi 3+ and Pb 2+ give rise to a very limited incorporation of these ions into the CdGa 2 Se 4 structure.…”