荧光粉YGaAG:Ce(Y2.96Ce0.04Al3.4Ga1.6O12)的热释光研究

Investigation on thermoluminescence of phosphor YGaAG:Ce(Y2.96Ce0.04Al3.4Ga1.6O12)

部分电子设备在使用或检测中需考虑电离辐射的综合影响,用热释光剂量计是一种测量电离辐射剂量的有效方式。荧光粉被广泛应用于电子设备中,本文尝试直接将荧光粉用作热释光剂量计。首先用高温固相反应法制作了发绿光的YGaAG:Ce(Y2.96Al3.4Ga1.6O12:0.04Ce)荧光粉,用线性升温法测量了荧光粉的热释光发光曲线和三维热释光谱;然后用热释光动力学方法拟合计算了材料中的电子陷阱相关参数,并系统测量了样品的剂量响应。拟合计算结果表明:材料中存在4种载流子陷阱,对应的激活能分别为0.83 eV、0.99 eV、1.15 eV和1.23eV,相应的频率因子分别为0.98×10^10 Hz、1.28×10^11 Hz、1.41×10^12 Hz和1.45×10^12 Hz。实测结果发现样品的发光峰温在185℃左右;已测得磷光体在辐照剂量0.1~200 Gy内,其热释光响应具有较好的线性,且估算其热释光探测灵敏度可能小于2 mGy。研究结果表明:该磷光体可作热释光剂量计材料,适合用于检测电子设备接受的电离辐射剂量。

[Background]Phosphor has become an important object of study in recent years due to their applications as potential laser crystal materials and packaging light emitting diode(LEDs).Phosphors are widely used in electronic devices,their effect of ionizing radiation to some electronic equipment needs to be evaluated in some conditions.One of the effective methods to measure the dose of ionizing radiation is thermoluminescence(TL).[Purpose]This study aims to investigate a kind of phosphor which can be directly used as a thermoluminescent dosimeter.[Method]First of all,green light emitting phosphors YGaAG:Ce(Y2.96Al3.4Ga1.6O12:0.04Ce)was prepared by the solid phase reaction method,and linear heating rate TL of the phosphor was measured.Then the linear heating rate method coupled with glow curve deconvolution(GCD)was used to calculate the activation energy and the frequency factor of electron traps within phosphor YGaAG:Ce.Finally,the dose response was measured systematically.[Results]Measured results show that there is only one remarkable and broad thermoluminescence peak in TL curve,and the temperature of this peak is about 185℃.Four traps are identified in the phosphor,and the activation energies are 0.83 eV,0.99 eV,1.15 eV and 1.23 eV,respectively,and the corresponding frequency factors are 0.98×10^10 Hz,1.28×10^11 Hz,1.41×10^12 Hz and 1.45×10^12 Hz,respectively.The TL response of the phosphor has good linearity in a large dose range(0.1~200 Gy),and the sensitivity of TL is about 2 mGy.[Conclusions]The research findings show that phosphor YGaAG:Ce has a broad application prospect in the radiation dose detection of electronic equipment.