溴化银乳剂中甲酸盐掺杂的位置效应研究

Position Effect of Formate Doped in Cubic Silver Bromide Grains

使用反馈式微机控制双注仪,在晶体生长过程的不同时刻,加入一定浓度的甲酸盐,制得了一系列甲酸根离子处于不同掺杂位置的立方溴化银微晶乳剂.对其感光性能的测试结果表明,(1)甲酸盐掺杂乳剂与未掺杂乳剂相比,感光度有显著提高;(2)甲酸根的掺杂位置越接近晶体表面,其感光度增益越大;(3)甲酸盐掺杂乳剂可同时与常规的硫加金化学增感和光谱增感进行协同增感;(4)光谱增感后的掺杂乳剂在延伸的光敏区内仍表现出明显的掺杂增感效应,但其增感倍率要低于乳剂在本征光敏区(蓝区)的增感倍率;(5)所有的掺杂乳剂,包括原始、硫加金和光谱增感的掺杂乳剂,它们的灰雾均保持在相当低的水平.

In the emulsifying process of silver bromide microcrystals in the double-jet apparatus controlled by a microcomputer, a specific quantity of formate was added at different time when the crystal growth to obtain a series of cubic AgBr emulsions in which formate ions were doped into different depths of AgBr microcrystals. The results from measurements of photographic properties of these emulsions showed: 1) that the sensitivities of formate-doped emulsions, relative to that of the undoped emulsion as the controlled one, were remarkably increased; 2) that the closer to the surface of grains the formate doped in AgBr grains was, the greater the sensitivities of the doped emulsions were; 3) that a significant cooperative sensitization of the internal doped formate with the surface sulfur-plus-gold and dye sensitizations was observed; 4) that the maximal sensitivity gain (Smax/S0) of undye-sensitized emulsions was greater than those of dye-sensitized ones; 5) that fog densities of all emulsions doped by formate, including those primitive, sensitized by sulfur-plus-gold and by green-sensitive dye, were kept in a reasonably low level.