EFFECT OF CAO AND BI ₂ O ₃ CONTENTS ON THE PHOTOLUMINESCENCE PROPERTIES OF BI ₂ O ₃ AND ZNO-CO-DOPED CA2+X GA ₄ O8+X PHOSPHORS

Building upon the work of Liu et al., who successfully synthesized the Ca 3 Ga 4 O[Formula: see text] Bi 2 O[Formula: see text] ZnO phosphor exhibiting green emission at approximately 500[Formula: see text]nm, this study further investigates the influence of CaO content on both the crystal structure and luminescent behavior of this material system. A series of phosphors with compositions Ca[Formula: see text]Ga 4 O[Formula: see text] Bi 2 O[Formula: see text] ZnO (where [Formula: see text]–1.0) were synthesized via the conventional solid-state reaction method. The photoluminescence excitation (PLE) and emission (PL) intensities exhibited a distinct nonlinear dependence on CaO concentration, rising with increasing CaO content, reaching a maximum at [Formula: see text], and then gradually declining at higher x values. After identifying [Formula: see text] as the optimal CaO composition yielding the strongest PLE and PL responses, the study proceeded to examine the effect of varying Bi 2 O 3 content on the luminescent characteristics of this optimized Ca[Formula: see text]Ga 4 O[Formula: see text] ZnO phosphor. To elucidate the relationship between structural evolution and optical performance, X-ray diffraction (XRD) was employed to analyze the crystal structure and phase composition, while photoluminescence (PL) spectroscopy was utilized to determine excitation and emission behaviors. The PLE analysis results revealed that all samples exhibited a consistent excitation peak near 340[Formula: see text]nm, with PL emission peaks slightly shifting within the 474–477[Formula: see text]nm range. This study deepens the understanding of how compositional modulation affects the crystal structure and luminescent efficiency of Bi 2 O 3 - and ZnO-co-doped Ca[Formula: see text]Ga 4 O[Formula: see text] phosphors, offering meaningful insight into the underlying mechanisms governing their photoluminescent properties.