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采用高温固相法在弱还原气氛下制备了Ba0.955Al2Si2-x Gex O8∶Eu2+(x=0.0~1.0)系列荧光粉,研究了Ge4+置换Si 4+对其晶体结构和光谱特性的影响。Ge4+以类质同相替代Ba长石(BaAl2Si2O8)晶格中的Si 4+形成连续固溶体,晶胞参数a、b、c、β和晶胞体积V随Ge4+置换量呈线性递增。荧光激发谱为宽带,位于230~400nm处,可拟合成4个峰,最大峰值位于332nm;随着Ge4+置换量的增加,半高宽(FWHM)从93nm减小到80nm。发射光谱位于375~600nm,可由422nm和456nm两峰拟合而成,最大峰值位于434nm;随着Ge4+置换量Si 4+进入基质晶格,造成Eu-O距离变小,发光中心Eu2+所处晶体场增强,5d轨道能级分裂变大,最低发射能级下移,两拟合峰均线性红移。
Ba0.955Al2Si2-xGexO8:Eu2 + (x = 0.0-1.0) phosphor was prepared by low-temperature solid-state reaction in a weak reducing atmosphere. The effects of Ge4 + substitutional Si 4+ on its crystal structure and spectral properties were investigated. Ge4 + replaces Si 4+ in the BaAl 2 Si 2 O 8 lattice with the same phase and forms a continuous solid solution. The unit cell parameters a, b, c, β and unit cell volume V increase linearly with the amount of Ge 4 + substitution. The fluorescence excitation spectrum is broad band, located at 230-400 nm, which can be fitted into four peaks with the maximum peak at 332 nm. FWHM decreases from 93 nm to 80 nm with the increase of Ge 4 + substitution. The emission spectra are located at 375-600nm, which can be fitted by two peaks at 422nm and 456nm with the maximum peak at 434nm. With the substitution of Ge4 + for Si4 + into the host lattice, the Eu-O distance becomes smaller and the Eu2 + The field increases, the splitting of the 5d orbit level becomes larger and the lowest emission level goes down, and both fitting peaks are linearly redshifted.