The broadband NIR emission properties of Bi doped La2O3-Al2O3-SiO2 glass

► Broadband NIR emission of Bi in lanthanum aluminosilicate glass was first studied in this work. ► Existence of low valence state was demonstrated by X-ray photoelectron spectroscopy. ► Mechanism of Bi-ion NIR emission was explored based on series of experiments and energy matching.