Growth and Properties of Defect‐Chalcopyrite CdGa₂Se₄ Crystals

Abstract

CdGa2Se4 crystal, with the structure of defect‐chalcopyrite, is a promising optical and photoelectric material. Single crystal with size of Φ11×60 mm3 was grown successfully by vertical Bridgman method. The as‐grown crystal was characterized with X‐ray diffraction (XRD), energy dispersive X‐ray Spectroscopy (EDS), and transmission spectra etc. The results show that the crystalline quality of the crystal is very good, and the atomic ratio is Cd:Ga:Se=1:2.12:4.05, which is close to the ideal stoichiometry. The crystalline quality and the chemical composition of the cracked section near the end of the crystal were also measured and the cracking reason was analyzed. The transparency range of the crystal was revealed for the first time. The transmittance of a 3.6 mm sample is above 65% in the range of 5 to 12 μm, which demonstrate the high optical quality of the crystal. Based on the transmission spectra, the refractive index and the energy bandgap were calculated to be 2.5 and 1.97 eV respectively.

Refined Synthesis and Single Crystal Growth of PbGa2Se4by Chemical Vapor Transport Method for Photodetection

“…[15] Therefore, ternary chalcogenide PbGa 2 Se 4 with high resistivity, photosensitivity, and excellent nonlinear properties, exhibits potential applications in optoelectronic and nonlinear optical devices. Besides, up to now, various crystal growth techniques have been employed thus far to synthesize II-III 2 -VI 4 type ternary metal chalcogenides, such as Bridgeman growth, [13,[16][17][18] vapor phase deposition, [19,20] and solution growth method. [21,22] However, the ternary compound PbGa 2 Se 4 was formed by the peritatic reaction (L + 𝛼(Ga 2 Se 3 ) → PbGa 2 Se 4 ) and possessed a narrow homogeneity region, which brings significant challenges in obtaining pure phase.…”

“…Besides, up to now, various crystal growth techniques have been employed thus far to synthesize II‐III 2 ‐VI 4 type ternary metal chalcogenides, such as Bridgeman growth, [ 13,16–18 ] vapor phase deposition, [ 19,20 ] and solution growth method. [ 21,22 ] However, the ternary compound PbGa 2 Se 4 was formed by the peritatic reaction $$( {L + {{\alpha}}( {G{a}_2S{e}_3} ) \to PbG{a}_2S{e}_4} )$$ and possessed a narrow homogeneity region, which brings significant challenges in obtaining pure phase.…”