微柱状CsI闪烁薄膜热蒸发生长工艺

Growth process of CsI scintillating films with micro-columnar structure by thermal evaporation

采用真空热蒸发法在石英玻璃基片上制备了具有特殊微柱状结构的碘化铯闪烁薄膜。运用扫描电子显微镜、X射线衍射仪和荧光光谱仪分别对碘化铯薄膜的形貌、结构及发光性能等进行了表征与分析。结果表明:在基片温度为260℃、沉积速率为3 nm.s-1时,所生长的碘化铯薄膜具有理想的微柱形貌、沿(110)晶面的择优取向和良好的透射性能;紫外光激发下,发射主峰为438 nm,X射线激发下,发射主峰为315nm,说明短波段发射峰需要的激发能量较高,而长波段发射峰对紫外光激发更为敏感。

CsI scintillating films with micro-columnar structure were deposited on the silica glass substrates by thermal evap- oration. Their morphologies, crystal structures and luminescent properties were analyzed with X-ray diffraction, scanning electron microscope and emission spectrum. The results showed that for substrate temperature of 260℃ and the deposition rate of 3 nm · s^-1 , the film was deposited wouldhave an ideal micro-columnar morphology, （110） preferred orientation and good transmittance. The CsI film would exhibit two emission peaks at 303 nm and 438 nm under UV excitation, where the later peak was dominant. However, the former peak would shift to 315 nm and became the main one under X-ray excitation, whilst the peak near 438 nm was quite small. The phenomenon indicated that the emission peaks at the short wavelength and the long wavelength could be excited effectively with X-ray and UV, respectively.