The trap bag concept of afterglow luminescence

Yih-Ping Huang,Jeng-Wen Lin

doi:10.1038/s41598-017-07789-2

Abstract

This article explains the behavior of afterglow luminescence using the trap bag concept, in which a constant phosphor dose contains a presumed bag with the ability to capture or release electrons through its opening. Luminescence is emitted as the bag releases the captured electrons. The electron-holding capacity is determined by the irradiation conditions, the width of the opening, and the electron activation; these factors are inherent properties of the long persistent luminescence (PLUM) dose and are affected by the thermal status. During the afterglow stage, higher temperatures may result in a wider opening and increased activation of electrons released from the bag, thus creating a higher light intensity and leading to the quicker exhaustion of the electrons within. In contrast, the opposite phenomenon will occur at lower temperatures. This article provides a detailed explanation of the trap bag concept at various thermal statuses and provides a method for delaying the afterglow peak profile through temperature change. Experimental tests were performed to confirm the proposed concept.

Highlights

Strontium aluminate phosphors (SrAl2O4: Eu2+, Dy3+) demonstrate excellent afterglow luminescence properties[1]
In previous afterglow behavior studies, the level positions of the trapped electrons have been exploited to predict some of the basic behaviors of a phosphor dose
This article provides a simple and novel concept of a bag with an opening to explain the afterglow decay profile that correlates with temperature change, while exploiting applications such as stress measurement in order to produce a postponed afterglow decay curve

Summary

OPEN The trap bag concept of afterglow luminescence

This article explains the behavior of afterglow luminescence using the trap bag concept, in which a constant phosphor dose contains a presumed bag with the ability to capture or release electrons through its opening. In the low temperature range between 0 °C and −10 °C, after 30 min into the afterglow process the luminescence intensity becomes very low This phenomenon indicates that low temperature can result in a tightening of the bag’s opening and a reduction of electron activation, minimizing the number of electrons released from the bag. TL-time plot showing four curves that represent tests performed with an initial excitement at 90 °C, 10 minutes later after ending excitation their temperatures were lowered to 0 °C for 30, 60, 90, and 180 minutes respectively before increasing the temperature back to 90 °C. opening of a trap bag and almost completely contain the held electrons, and that the bag can be opened in order to resume afterglow behavior by increasing the temperature. This figure indicates that minimizing the electron consumption at the early emission stage can be beneficial to the afterglow as the temperature rises

Discussion and Conclusion

Findings

Additional Information