K_2Te日盲紫外阴极研究(英文)  

Study of K_2Te Solar Blind Ultraviolet Photocathode

作　　者：李晓峰[1,2] 赵学峰[2] 陈其钧 褚祝军[2] 黄建民[2] 

机构地区：[1]微光夜视技术重点实验室,陕西西安710068 [2]北方夜视技术股份有限公司,云南昆明650217

出　　处：《红外技术》2014年第12期967-972,共6页Infrared Technology

基　　金：微光夜视技术重点实验室基金"多碱光电阴极研究",编号:J2011016

摘　　要：叙述了K2Te日盲紫外阴极的制作工艺并制作了K2Te日盲紫外阴极，测量了K2Te日盲紫外阴极的光谱响应、光谱反射率、光谱吸收率和250 nm波长激发条件下的荧光谱。与Cs2Te日盲紫外阴极相比较，K2Te日盲紫外阴极的光谱响应较低，而且光谱响应的峰值波长更短，长波截止波长也更短。K2Te日盲紫外阴极光谱响应的峰值波长位于215 nm，长波截止波长位于305 nm，而Cs2Te日盲紫外阴极光谱响应的峰值波长位于250 nm，长波截止波长位于323 nm。另外K2Te日盲紫外阴极的日盲特性更好，633 nm波长的光谱响应为10－6 mA/W的数量级，较Cs2Te日盲紫外阴极低一个数量级。光谱反射率的测量结果表明，K2Te日盲紫外阴极的光谱反射率曲线形状与Cs2Te日盲紫外阴极的光谱反射率曲线形状相似，区别是整个光谱反射率曲线向短波方向移动，且波长越长，移动越大。另外K2Te日盲紫外阴极的光谱反射率在200～450 nm的波长范围内均高于Cs2Te日盲紫外阴极的光谱反射率，由此可推断出K2Te 紫外阴极的折射率高于Cs2Te 紫外阴极的折射率，并且波长越长，折射率差别越大。光谱吸收率的测量结果表明，K2Te 日盲紫外阴极的吸收率低于Cs2Te 紫外阴极的吸收率。光谱吸收率越高，光谱响应也越高，与光谱响应的测量结果相吻合。荧光谱的测试结果表明，在250 nm 波长激发条件下，在200～450 nm 的波长范围内，K2Te 紫外阴极的荧光弱于Cs2Te 紫外阴极的荧光，原因是K2Te 阴极的吸收率低于Cs2Te 紫外阴极的吸收率。光谱吸收率越高，荧光越强，这同样与光谱响应的测试结果相吻合。所以K2Te 日盲紫外阴极与Cs2Te 日盲紫外阴极相比，尽管光谱响应较低，但日盲特性更好，因此也可用作为日盲紫外探测器的紫外阴极。In this paper the making process of K2Te solar blind ultraviolet photocathode is described and its behavior such as spectral response, spectral absorptance and the fluorescence spectra under the excitation of 250nm wavelength UV light were measured. The measured results are compared with corresponded results of Cs2Te solar blind ultraviolet photocathode. Our findings suggest that the spectral response of K2Te solar blind ultraviolet photocathode is lower, and the peak wavelength of the spectral response is shorter, moreover the long-wavelength threshold is shorter as well. The peak wavelength of the spectral response is 211nm, the long-wavelength threshold is 298nm for the K2Te photocathode, while the peak wavelength of the spectral response is 250nm, and the long-wavelength threshold is at 347nm for the of Cs2Te photocathode. In addition, K2Te photocathode has better solar blind property since its spectral response at 633nm is in the order of magnitude of 10^-6mA/W, almost two orders of magnitude lower than that of Cs2Te photocathode. The findings of spectral absorption indicate that the photon absorption of K2Te photocathode is lower than that of Cs2Te photocathode. The higher the spectral absorption, the higher the spectral response is. This matches our findings of spectral response. The findings on fluorescence spectra indicate that under the UV light excitation of 250nm wavelength and measured within the wavelength range of 200 to 450 nm; the fluorescence of K2Te photocathode is less intense than that of Cs2Te ultraviolet cathode, which matches our findings of the spectral response and spectral absorbance well. Thus, compared with Cs2Te solar blind ultraviolet photocathode, although the spectral response of K2Te solar blind ultraviolet cathode is lower, the solar blind property is better and therefore is potentially very useful for solar blind ultraviolet detectors.

关 键 词：K2Te阴极 Cs2Te阴极 光谱响应 吸收率 荧光谱 

分 类 号：O462.3[理学—电子物理学]