Novel ternary semiconductor CdLa 2X 4 (X=S or Se) single crystal with efficient second harmonic generation in the visible spectral range

摘要

AbstractComprehensiveab-initocalculations are performed to investigate the suitability of the non-centro-symmetric CdLa2S4and CdLa2Se4for using as nonlinear optical crystals in visible spectral range. The calculations reveal the direct band gap nature of both compounds with large absorption coefficient (104?cm?1). The absorption edges of CdLa2S4and CdLa2Se4occur at λ?=?579.3?nm and λ?=?670.1?nm, and the optical band gaps are estimated to be 2.14?eV and 1.85?eV for CdLa2S4and CdLa2Se4, respectively. CdLa2S4exhibits SHG of about two times of the well-known KH2PO4(KDP) single crystals which exhibits a nonlinear coefficient of 0.39 p.m./V. Whereas CdLa2Se4exhibits SHG very close to the experimental value of that for the well-known KTiOPO4(KTP) which exhibits a nonlinear coefficient of about 14.6?±?1.0.Highlights?CdLa2S4and CdLa2Se4active NLO crystals in the visible light spectral range.?CdLa2S4and CdLa2Se4possesses direct band gap with large absorption coefficient.?Absorption edges of CdLa2S4and CdLa2Se4occurs at λ?=?579.3?nm and λ?=?670.1?nm.?CdLa2S4exhibits SHG of about two times of KH2PO4(KDP).?CdLa2Se4exhibits SHG very close to the experimental value of KTiOPO4(KTP).]]>