AgX:I微晶的光电子衰减时间分辨谱测量

Measurement of Photoelectron Decay Time-resolved Spectrum of AgX:I Crystals

利用高时间分辨的微波吸收薄膜介电谱测量技术,采用自行设计的光电子时间分辨谱测量装置(时间分辨率达到1 ns),精确地测量了不同Agx:I材料在35 ps超短脉冲激光曝光后产生的自由光电子和浅俘获光电子随时间衰减的光电子衰减时间分辨谱,分析了不同的[I-]掺杂条件对材料光电子时间特性的影响关系,得到了影响Agx:I微晶光电子时间特性的最佳[I-]掺杂条件。对立方体AgCl乳剂来说,[I-]含量0.5％,掺杂位置80％Ag处时,乳剂的光电子寿命最长。而对T-颗粒AgBr乳剂而言,[I-]含量3％时,乳剂的光电子寿命最长。碘化物对光电子寿命增大的影响是由于碘化物离子可以作为缺陷电子陷阱,这就使得银簇上的反应减小,当碘化物大于3％时,这一效应由于碘化物团簇的形成而消失。

Microwave absorption and film dielectric spectrum detection technology, and the photoelectron decay time-resolved spectrum measurement equipment with a high time resolution (1 ns) were used to measure the photoelectron decay time-resolved spectrum of free electrons and shallow-trapped electrons generated in various AgX: I crystals illuminated by 35 ps super short pulse laser in this paper. The influence of [I-] doping condition on the photoelectron decay temporal characteristics of AgX materials was analyzed and the optimal [I-] doping condition was obtained. For cubic AgCl emulsion, the free electron lifetime reached maximum when iodide content was 0.5 %. For T-grain AgBr emulsion, the free electron lifetime reached maximum when iodide content was 3 %. The effect of iodide on the photoelectron lifetime is because iodide ions can act as a trap for defect electrons. This leads to reduced reaction on the silver clusters. For iodide concentrations higher than 3 %, this behavior disappears due to the formation of iodide agglomerations.