新穎發紫外光螢光粉之製備與發光特性之研究

Abstract

為因應綠能與環保時代的來臨，本研究主旨為開發真空紫外波長可激發之新穎紫外光之無機螢光體，並探討其發光相關原理與機制，進而評估其在製作紫外線殺菌元件之應用潛力。本論文所探討之重點為迄今未曾被報導且可供準分子氙氣放電燈(Xenon excimer discharge lamp)激發之磷酸鹽、鹵磷酸鹽、鋁酸鹽、與硼酸鹽為基質之紫外光螢光材料。 除利用X-光繞射與電子顯微鏡進行螢光材料特性鑑定分析之外，本研究獨特重點為利用同步輻射研究中心真空紫外光源進行發光波長屬UVA波段的Na(Y,Ce)FPO4、UVB波段的(Y,Gd,Pr)P3O9、Na(Y,Gd,Pr)FPO4、Ca(Y,Pr)Al3O7與屬於UVC波段的(Y,Pr)P3O9、Na(Y,Pr)FPO4與KCa(Y,Pr)(PO4)2等多種螢光體發光特性鑑定。 在254 nm波長激發下，Na(Y,Ce)FPO4發射源自於Ce3+的4f1→5d1躍遷波長為351 nm的UVA紫外光。在172 nm波長激發下，(Y,Gd, Pr)YP3O9與Na(Y,Gd,Pr)FPO4分別發射源自Gd3+的6P7/2→8S7/2躍遷的波長為313 nm的UVB紫外光。而在真空紫外光源激發下，Ca(Y,Pr)Al3O7、(Y,Pr)P3O9、KCaY(PO4)2、Na(Y,Pr)FPO4發射源自於Pr3+的4f15d1→4f 2 (3HJ, J = 4,5,6)躍遷的UVC紫外光，其放射波長深受主體鍵結與晶體結構特性的影響。

Facing the challenge of global warming and environmental concern, the development of green luminescent materials has been an important issue in phosphors research. This research is attempted to develop environmental friendly ultraviolet-emitting materials, particularly those are not disclosed previously in the literature and excitable with xenon excimer discharge devices, for the applications of phototherapy, sterilization, and disinfection. We have explored and investigated the luminescence mechanism of several series of UV-emitting phosphors, including rare earth-doped aluminates, borates, and phosphates. In addition to X-ray diffraction technique and electron microscopy, the vacuum ultraviolet (VUV) light source provided by National Synchrotron Radiation Research Center (NSRRC) has been used to explore and investigate the luminescence of UV-emitting phosphors, such as UVA-emitting Na(Y,Ce)FPO4; UVB-emitting (Y,Gd,Pr)P3O9, Na(Y,Gd,Pr)FPO4, and Ca(Y,Pr)Al3O7 and UVC-emitting (Y,Pr)P3O9, Na(Y,Pr)FPO4 and KCa(Y,Pr)(PO4)2. Under excitation at 254 nm, Na(Y,Ce)FPO4 emits UVA radiation centered at 351 nm, which is attributed to the 4f1→5d1 transition of Ce3+. Under excitation at 172 nm, (Y,Gd,Pr)YP3O9 and Na(Y,Gd,Pr)FPO4 were found to emit UVB light centered at 313 nm which was attributed to the 6P7/2→8S7/2 of Gd3+.Under VUV excitation, Ca(Y,Pr)Al3O7, (Y,Pr)P3O9, KCaY(PO4)2, and Na(Y, Pr)FPO4 were found to emit UVC light, which was found to be due to the 4f15d1 →4f 2 (3HJ,J=4,5,6) transition of Pr3+. The emission wavelength of all types of UV radiation was found to be crucially dependent on the bonding and crystal structure of the host matrix.