Primary Processes in Photoconductivity Studied by Electromodulation Spectroscopy.

研制了一种高灵敏度的分光光度计，其吸光度分辨率高达10 ~（-5）。它已被证明是一个强有力的研究工具，在测定微小的吸光度变化，例如。G.即外加电场。本文研究了x型H_2酞菁的电吸收光谱。结果表明，在第一个吸收峰上表现出较大电调制的酞菁具有较高的载流子产生效率，并研究了电场对荧光的调制。结果清楚地表明，调制不是由于施加的场，而是由于从电极注入的电荷。由于注入电荷引起的强烈的猝灭现象似乎表明具有CT态特征的最低激发单重态在注入电荷周围的强场中解离，从整体上阐明了CT态在所研究材料中光生载流子产生、光吸收调制和荧光调制中的重要作用。

A highly sensitive spectrophotometer has been developed, which has a resolution in absorbance as high as 10-5. It has proved to be a powerful research tool in determioning minute absorbance changes by, e. g. , an applied electric field. The electroabsorption spectrum of x-form H_2 Phthalocyanine has been investigated. The results indicate phtahlocyanines that exhibit a large electromodulation in their first absorption peak tend to have high efficiency of charge carrier generation.Also, modulation of fluorescence by an electric field has been studied. The results clearly show that the modulation is not due to an applied field, but due to charges injected from the electrodes. The anomalously sttong quenching due to injected charge seems to indicate that the lowest excited singlet state, which has a CT state character, disociates in the strong field surrounding the injected charges.As a whole, important participation of CT states in photocarrier generation, modulation of light absorption, and fluorescence, odulation, in the materials studied has been clarified.