铱盐在AgBr乳剂中的作用

用(NH_4)_3IrCl_6(Ⅲ)和(NH_4)IrCl_6(Ⅳ)分别对立方体AgBr乳剂颗粒表面和内部进行敏化,用表面显影和内部显影的方法,对铱盐在乳剂颗粒中的作用进行了研究。实验表明,经铱表敏的AgBr乳剂表面感光度增加,而铱内敏的AgBr乳剂表面感光度降低,内部感光度增加;铱内敏并经灰化的乳剂在曝光后能形成直接正像。这是因为经化学灰化的铱内敏乳剂在曝光后,光生电子被乳剂颗粒内部的铱中心捕获而形成内潜影,光空穴则破坏颗粒表面的灰化中心,使其不能显影。因此,我们认为铱在乳剂颗粒内部起着电子陷阱的作用。

THE ROLE OF IRIDIUM IN AgBr EMULSION

The role of iridium salt in AgBr emulsions was investigated in this work. It was prepared that monodisperse cubic AgBr grain with edge length of 0.3*m. which are surface and internal sensitized with (NH4)3IrCl6or (NH4)2IrCl6; It was found that the surface sensitivity of the emulsion with Ir surface sensitization is increased. The surface sensitivity of the emulsion with Ir internal sensitization is decreased, but its internal sensitivity is increased. The Ir internal sensitized and fogged emulsion can form direct positive image after exposure and development. The Photoelectrons may be trapped by the internal Ir-centers forming internal latent image and the surface fog centers on the grain may be destroyed by the holes.