化学增感对光电子时间分辨谱的影响

Effects of Chemical Sensitization on Photoelectron Time-Resolved Spectrum

利用微波吸收相敏检测技术,对AgBrI T颗粒乳剂中光电子时间行为进行了检测,并获得了自由光电子与浅束缚光电子的时间分辨谱。实验结果表明,在加入Na2 S2 O3相同的条件下S与S +Au增感中心所起的电子陷阱作用不同,S增感中心所起的作用为深电子陷阱,增感中心由于增加了对光电子的深束缚,从而造成自由光电子与浅束缚光电子的衰减加剧;S +Au增感中心所起的作用为浅电子陷阱,增感中心通过暂时束缚光电子有效降低了光电子与光空穴的复合,减缓了自由光电子与浅束缚光电子的衰减,可见加入KAuCl4 后形成的S +Au增感中心陷阱深度要比S增感中心的陷阱深度浅。从光电子时间分辨谱的变化可以看出S与S +Au增感中心在衰减曲线的不同时域中对光电子衰减的作用表现不同。

The time-resolved spectra of free photoelectrons and shallow-trapped electrons in the T-grains AgBrI emulsion were simultaneously detected with microwave absorption and dielectric spectrum detection technique. The results indicate that the electron trap effects of sulfur sensitization centers and sulfur-plus-gold sensitization centers are different with equal quantities of Na2S2O3 added. The sulfur sensitization centers acted as a deep electron trap to pick up the electronic decay because of increasing the number of deep trapped electrons, while the sulfur-plus-gold sensitization centers as a shallow electron trap decrease the electronic decay through effectively controlling the recombination between the electrons and the holes. The depth of sulfur-plus-gold sensitization center is shallower than that of sulfur sensitization center after the KAuCl4 is added. The effects of sulfur sensitization center and sulfur-plus-gold sensitization center on the photoelectron decay are different in different sections of decay curves through the change in electron time-resolved spectra.