First-Principle Calculations and Experimental Investigation of Structure, Defect, and Spectra Properties of Yb3+-doped NaGd(1–x)La(x)(MoO4)2 Composite Laser Crystals

• DOI: 10.1021/acs.cgd.4c00732
• Publication Date: 2024-08-14T09:02:55Z
• Authors: Chuancheng Zhang; Shoujun Ding; Wenzhi Su; Miaomiao Wang; Haitang Hu; Yong Zou; Wenpeng Liu; Qingli Zhang
• Keywords: Crystal (programming language)

Inhomogeneous broadening in disordered crystals has been widely recognized as a successful approach to enhance the spectral bandwidth of rare earth ions optical spectra, and Yb3+-doped mixed laser are known ultrafast pulse materials have emerged hotspot recently. In this study, sodium gadolinium/lanthanum double molybdate NaGd(1–x)La(x)(MoO4)2 with x = 0.3, 0.5, 0.9 were grown by Czochralski (Cz) method. The structure as-grown was investigated XRD, SEM, FT-IR, Raman experiments. spectroscopic properties, including absorption, emission, fluorescence decay characteristics, thoroughly. NaGd0.5La0.5(MoO4)2 (NGLM) composite crystal exhibited an exceptionally broad absorption which reaches 70 nm (fwhm) at 980 nm, exceeding those NaGd(MoO4)2 (NGM) NaLa(MoO4)2 (NLM). Additionally, electronic structures (band density states) NGM, NGLM, NLM determined from first-principles method combined PBE function. calculations defect formation energies under O-poor O-rich conditions demonstrate that +2 defects easily generated undoped NGM prepared reducing atmospheres, calculation properties reveals black color without annealing is mainly attributed intraband transitions between induction states VBM or CBM. Moreover, lifetimes excited energy level 2F5/2 Yb3+ examined different experimental environments obtain intrinsic radiative lifetime, emission cross section calculated 2.25 × 10–20 cm2 1016 nm. features Yb3+:NaGd(1–x)La(x)(MoO4)2 indicate potential applications for tunable through slight regulation engineering strategy.