潜影形成过程中的空穴及其转换

最近几年，在研究卤化银体系的潜影形成效率时，在如何对待和处理光生空穴问题上出现了一些突破传统思路并具有开拓性的方法，我们把它称之为“空穴－电子转换”法。这种方法的关键是寻找或设计一种“化学转换器”。这种转换器既能捕获空穴，消除或减少潜影形成过程中由于电子与空穴的复合造成的电子损失，又能经过它的转换产生并释放出额外电子或某种电子载体（如自由基）促进潜影的形成，起到一举两得显著提高卤化银乳剂感光度的作用。本文对当前已有的3种化学转换器的研究进展进行了综合评述，望引起国内科学家的密切关注。

CONVERSION OF POSITIVE HOLE TO ELECTRON IN THE PROCESS OF LATENT IMAGE FORMATION

In the imaging system of silver halide, photon generated positive holes have been considered as a kind of species which play a negative role to cause inefficiency of latent image formation via recombination with electrons, regressive reaction with silver clusters and so on. Recently, some kind of novel sensitization technique that might be called as a conversion of hole to electron has been developed and are greatly interested in. So far 3 kinds of compounds have been found to act as a chemical converter. These are: 1) silver dimmer (Ag 2); 2) compounds of carboxylic acids including formic acid; 3)FED compounds, i.e fragmentable two electron donors. Each of these compunds possesses two elementary functions: trapping hole and releasing an extra electron through conversion when it is adsorbed or introduced into silver halide crystals. In this paper, features, mechanism and effect etc. of these converters are reviewed.