零维Sb^(3+)掺杂Rb_(7)Bi_(3)Cl_(16)金属卤化物的三重态自陷激子发射

Zero-dimensional Sb^(3+)doped Rb_(7)Bi_(3)Cl_(16) metal halides with triplet self-trapped exciton emission

低维金属卤化物由于其优异的光学性能吸引了广泛的关注,尤其是零维金属卤化物,由于其孤立八面体的结构特性能提高辐射复合概率.本文报道了一种零维金属卤化物Rb_(7)Bi_(3)Cl_(16),通过Sb^(3+)掺杂后,在613 nm处出现宽带的橙黄色发射,当Sb^(3+)掺杂浓度为30%时该最高光致发光量子效率可达30.7%.这种高效发光来源于电子与晶格的强相互作用产生的自陷激子,进一步通过光学性能表征研究自陷激子发光的具体物理机制和能量传递过程,单重态^(1)P_(1)上的电子态通过系间窜越过程弛豫到三重态^(3)P_(1),强烈的橙黄色发射来自于三重态^(3)P_(1)→^(1)S_(0)辐射复合过程.此外,Sb^(3+)掺杂Rb_(7)Bi_(3)Cl_(16)具有良好的稳定性,采用Sb^(3+):Rb_(7)Bi_(3)Cl_(16)为发光材料的发光二极管(LED)色坐标为(0.4886,0.4534),色温为2641 K,在LED领域具有重要应用前景.

Low-dimensional metal halides have attracted extensive attention due to their excellent optical properties,especially zero-dimensional metal halides,which can improve the radiation recombination probability due to the characteristics of their isolated octahedral structures.In this paper,we report a zero-dimensional metal halide Sb^(3+)doped Rb_(7)Bi_(3)Cl_(16) with a broadband orange-yellow emission at 613 nm.When the Sb^(3+)doping concentration is 30%,the highest photoluminescence quantum yield of the system reaches 30.7%.This high-efficiency luminescence is derived from the self-trapped excitons generated by the strong interaction between electrons and the crystal lattice.The specific physical mechanism and energy transfer process of self-trapped exciton luminescence are further studied through characterizing the optical performances.The electronic states in the singlet ^(1)P_(1) level are relaxed to the triplet ^(3)P_(1) via an intersystem crossing process,and the strong orange-yellow emission comes from the triplet state ^(3)P_(1)→^(1)S_(0) radiation recombination process.In addition,Sb^(3+)doped Rb_(7)Bi_(3)Cl_(16) has satisfactory environmental stability,the Sb^(3+):Rb_(7)Bi_(3)Cl_(16)-based light-emitting diodes(LED)are fabricated here in this work,and the color coordinates and correlated color temperature of the LED are(0.4886,0.4534)and 2641 K,respectively.The highly efficient and stable Sb^(3+)doped Rb_(7)Bi_(3)Cl_(16) is expected to be used in solid-state lighting and display fields.