摘要
描述了ZnSxSe1-x光盲紫外液晶光阀的结构和工作原理 ,并从器件的电学模型出发 ,着重讨论了整体器件对ZnSxSe1-x光敏层的特殊要求。采用分子束外延技术在ITO导电玻璃上制备了具有 (111)面定向生长结构的ZnSxSe1-x多晶薄膜 ,通过控制反应时的生长参数 ,制备出了符合器件设计要求的光敏层薄膜。室温下 ,该薄膜的紫外 /可见光响应对比度大于10 3 ;响应波长截止边可通过控制薄膜中的Se组分 ,在 (36 0～ 4 10 )nm范围内连续可调 ;薄膜的暗电阻率在 (4 32× 10 9～ 2 0 3×10 11)Ω·m之间 ,并随着晶粒的增大而减小 ;在液晶光阀工作的低频段 (<2 0 0Hz) ,其光 /暗阻抗比在 0 2 2～ 0 36之间。
The structure and operation of the novel ZnSxSe1-x visible blind ultraviolet liquid crystal light valve (UV-LCLV) were described. The optoelectronic requirements of ZnSxSe1-x photosensor for the device were derived and discussed from the UV LCLV electric model and equivalent circuits. Suitable polycrystalline ZnSxSe1-x film with (1ll) preferential growth orientation that provides a good matching with the requirements of LCLV were deposited on ITO coated glass by molecular beam epitaxy (MBE). Room temperature photo-responsivity measurements show that the visible rejection power can reach as high as 3 orders in magnitude. The cutoff wavelength of the response is between 360 nm 410 nm and follows the energy-gap dependence on the Se composition of the films. The results of DC resistivity measurement reveal that the resistivity of the films decreases as its crystal size increases. The results of AC impedance measurement further indicate that the ratio of photo/dark impedance of the films is between 0.22-0.36 at the low operation frequency (<200 Hz) of LCLV.
出处
《真空科学与技术》
EI
CSCD
北大核心
2002年第6期403-407,共5页
Vacuum Science and Technology
基金
中国自然科学基金资助项目 (No .5 9910 161981)
香港RGC研究资助局联合资助项目 (HKUST3 5 )
