Eu3+掺杂的Sr2CeO4发光材料的光致发光研究

利用高温固相反应法制备了Eu³⁺掺杂的Sr₂CeO₄样品,并对其吸附水前后的光谱特性进行了研究.结果发现,对于刚制备的Sr_2-xEu_xCeO_4+x/2样品, 在Ce⁴⁺—O^2-的电荷迁移激发中,只有强激发带(～35700cm^-1)与Eu³⁺离子间存在能量传递,而弱激发带 (～29400cm^-1)只是引起Ce⁴⁺—O^2-的电荷迁移发射;在Sr_2-xEu_xCeO_4+x/2样品吸附水后,Eu³⁺的线状吸收跃迁强度显著增加, Ce⁴⁺—O^2-两个激发带均向Eu³⁺离子传递能量. Ce⁴⁺—O^2-强激发带通过交换作用向Eu³⁺离子传递能量,而弱激发带与Eu³⁺离子间的能量传递机理是非辐射多极子近场力的相互作用. 关键词： 2-xEu_xCeO_4+x/2')" href="#">Sr_2-xEu_xCeO_4+x/2 发光性质 能量传递 吸附水

Investigation of the photoluminescence of Eu3+ doped Sr2CeO4 phosphor

Eu³⁺ doped Sr₂CeO₄ samples were prepared by a solid-state method and the luminescent properties of the samples with and without adsorbed moisture were investigated. When the Sr_2-xEu_xCeO_4+x/2 samples were prepared, it was found that only the excitation energy in the strong charge-transfer-state (CTS) band of Ce⁴⁺—O^2- peaking at about 35700cm^-1 was transferred to Eu³⁺ion while that in the weak CTS band of Ce⁴⁺—O^2- located at about 29400cm^-1 led to Ce⁴⁺—O^2- charge-transfer (CT) emission. After adsorption of moisture in the Sr_2-xEu_xCeO_4+x/2 samples, the intensity of Eu³⁺intra-4f⁶ absorption transition increased remarkably, the energy transfer took place from the two Ce⁴⁺—O^2- CTS bands to Eu³⁺ ion. The excitation energy in the strong Ce⁴⁺—O^2- CTS band was transferred to the Eu³⁺—O^2- CTS band through radiationless process involving exchange interaction, however, the weak Ce⁴⁺—O^2- CTS band caused the excitation to the Eu³⁺ excited levels through resonance radiationless process by a multipole interaction mechanism.