溴化银晶体光谱敏化光电流的研究和染料增感性能的判据

本文以AgBr晶体和菁染料为对象,对AgBr晶体的光电流进行了研究。实验发现,AgBr晶体经其本征吸收波长的光辐照后,可产生新的诱导吸收带。用诱导吸收带波长范围内的光辐照AgBr晶体,在非本征吸收区可测量到自敏化光电流。若染料吸附在AgBr晶体片上,则其敏化光电流将叠加在自敏化光电流上。增感染料对AgBr晶体的阳极和阴极光电导均有不同程度的敏化作用。本文在实验研究的基础上,提出了对染料增(减)感性能的判据S_D,比现有的一些判据更具有综合性。利用S_D—λ曲线可以较直观地对染料的增(减)感性能做出预测。本文利用S_D判据对一些实用增感染料及其组合作了分析。

STUDY ON SPECTRAL SENSITIZED PHOTOCURRENT OF AgBr CRYSTAL AND A CRITERION FOR SENSITIZING ABILITY OF CYANINE DYES

Using AgBr single crystal and cyanine dyes as substrate and spectral sensitizers respectively, the photocurrent pf AgBr was investigated in this paper. It was shown that the photo-induced absorption band can be observed when AgBr was irradiated in its intrinsic absorption range. The crystal presents self-sensitized photoconductivity in its nonintrinsic absorption band when it was exposed to the light in the induced absorption band. Both cathodic and anodic photocurrent of AgBr were sensitized by adsorbed cyanine dyes, therefore, the observed photo-current may include the self-sensitized photocurrent. On the basis of our experiments, a criterion for the sensitizing (or desensitizing) ability of cyanine dyes, S_D, was proposed. It may be more comprehensive than other known criteria. By means of the S_D-λ curves obtained, a prediction on the ability of spectral sensitization of dyes can be made. A set of practical dyes and their combinations were analysed with the S_D criterion in this work.