Zero-phonon line(ZPL)emission of Mn^(4+),without the participation of phonons,is tightly related to the host crystal structure.However,the intensity of the intrinsic ZPL is much weaker than that of Stokes and anti-Sto...Zero-phonon line(ZPL)emission of Mn^(4+),without the participation of phonons,is tightly related to the host crystal structure.However,the intensity of the intrinsic ZPL is much weaker than that of Stokes and anti-Stokes vibrational bands,and it always leads to a discontinuous emission peak.Regulating the ZPL of Mn^(4+)for a strong emission is very important but remains a challenge for perovskite-type oxides.Here,novel La_(1-x)BaxAl_(1-x)Ti_(x)O_(3):0.001Mn^(4+)(LBAT:0.001Mn^(4+),x=0-0.2)and La_(1-y)YyAl_(1-y)Ga_(y)O_(3):0.001Mn^(4+)(LYAG:0.001Mn^(4+),y=0-0.2)samples were successfully synthesized through a high-temperature solidstate reaction,and a tunable ZPL of Mn^(4+)was found by cationic pair substitution of Ba^(2+)-Ti^(4+)and Y^(3+)-Ga^(3+)for La^(3+)-Al^(3+)in LaAlO_(3):Mn^(4+).The ZPL intensity is related to the local symmetry around Mn^(4+)and the ZPL energy corresponds to the Mn-O bond distance and the O-Mn-O bond distortion.Through codoping Ba^(2+)-Ti^(4+),the ZPL at 710 nm is enhanced and the intensity increases continuously with increasing the x value,due to the local symmetric degree of Mn^(4+)decreasing slowly.However,Y^(3+)-Ga^(3+)co-doping induces a linear and quick increase in the intensity of ZPL at 704 nm with increasing y value,due to the local symmetric degree of Mn^(4+)decreasing quickly.The octahedral tilting distortion is very important for the local symmetry.Ba^(2+)-Ti^(4+)co-doping reduces octahedral tilting distortion,but Y^(3+)-Ga^(3+)co-doping induces a serious octahedral tilting distortion.Consequently,the ZPL emission exhibits an octahedraltilting dependent behavior.Mainly due to the larger distortion of the O-Mn-O bond,the energy of ZPL for LYAG:0.001Mn^(4+)is higher than that for LBAT:0.001Mn^(4+).The outcomes of this work provide a promising way to regulate the ZPL intensity and energy by tuning the local structure around Mn^(4+),and may have wide implications for Mn^(4+)-doped phosphors and solid-state lighting.展开更多
基金supported in part by the Natural Science Foundation of Liaoning Province(grant 2020-MS-081)National Natural Science Foundation of China(grants 51302032,51972047,52172112).
文摘Zero-phonon line(ZPL)emission of Mn^(4+),without the participation of phonons,is tightly related to the host crystal structure.However,the intensity of the intrinsic ZPL is much weaker than that of Stokes and anti-Stokes vibrational bands,and it always leads to a discontinuous emission peak.Regulating the ZPL of Mn^(4+)for a strong emission is very important but remains a challenge for perovskite-type oxides.Here,novel La_(1-x)BaxAl_(1-x)Ti_(x)O_(3):0.001Mn^(4+)(LBAT:0.001Mn^(4+),x=0-0.2)and La_(1-y)YyAl_(1-y)Ga_(y)O_(3):0.001Mn^(4+)(LYAG:0.001Mn^(4+),y=0-0.2)samples were successfully synthesized through a high-temperature solidstate reaction,and a tunable ZPL of Mn^(4+)was found by cationic pair substitution of Ba^(2+)-Ti^(4+)and Y^(3+)-Ga^(3+)for La^(3+)-Al^(3+)in LaAlO_(3):Mn^(4+).The ZPL intensity is related to the local symmetry around Mn^(4+)and the ZPL energy corresponds to the Mn-O bond distance and the O-Mn-O bond distortion.Through codoping Ba^(2+)-Ti^(4+),the ZPL at 710 nm is enhanced and the intensity increases continuously with increasing the x value,due to the local symmetric degree of Mn^(4+)decreasing slowly.However,Y^(3+)-Ga^(3+)co-doping induces a linear and quick increase in the intensity of ZPL at 704 nm with increasing y value,due to the local symmetric degree of Mn^(4+)decreasing quickly.The octahedral tilting distortion is very important for the local symmetry.Ba^(2+)-Ti^(4+)co-doping reduces octahedral tilting distortion,but Y^(3+)-Ga^(3+)co-doping induces a serious octahedral tilting distortion.Consequently,the ZPL emission exhibits an octahedraltilting dependent behavior.Mainly due to the larger distortion of the O-Mn-O bond,the energy of ZPL for LYAG:0.001Mn^(4+)is higher than that for LBAT:0.001Mn^(4+).The outcomes of this work provide a promising way to regulate the ZPL intensity and energy by tuning the local structure around Mn^(4+),and may have wide implications for Mn^(4+)-doped phosphors and solid-state lighting.
