ELECTROCHROMETIC STUDIES ON POLAR MULTILAYERS OF LIQUID CRYSTALLINE POLYMERS

Electrochrometic measurements were carried on the Z-type Langmuir-Blodgett films oftwo liquid crystalline polymers: mono-{6-[4-(phenylazo) naphthyloxy] hexyl} (1a) andmono-{6-[4-(anthraquinone-1-azo) naphthyloxy] hexyl} (2a) ester of polymaleic acid. Itwas found that for both polymers, poling fields parallel and antiparalle1 to dipole momentsof the polymer side chains induce red and blue shift in absorption bands, respectively. Forpolymer la blue shift is accompanied by absorbance increase, while red shift by absorbancedecrease;but for polymer 2a only decrease in absorbance is observed. A simple model wasproposed to analyze the results.     

n-GaAs(100)、Si(111)表面修饰卟啉分子的光致界面电荷转移特性的研究

利用表面光电压谱研究了四碘化四-(4-三甲胺苯基)卟啉(TTMAPPIH₂)修饰n-GaAS(100)和n-Si(111)半导体表面的光致界面电荷转移特性,结果表明,n-GaAs(100)表面修饰TTMAPPIH₂分子的光致界面电荷转移效率远比n-Si(111)表面修饰的高,并且发现在该卟啉分子的非吸收区也有明显的光致界面电荷转移现象,而与n-Si(111)间则没有这种转移特性。用电化学测量和UV光谱确定了TTMAPPIH₂相对于n-GaAs(100)、n-si(111)的能级位置关系,对TTMAPPIH₂分子与n-GaAs(100)和n-Si(111)间的不同光致界面电荷转移特性进行了解释。