Photoreceptor nucleus

This refers to the locations in silver halide grains used in silver halide photography where latent image centers are likely to form. When sulfur sensitization, a type of chemical sensitization, was discovered, it was thought that silver sulfide nuclei were formed on the particle surface, and these were named photosensitive nuclei. It was later discovered that these were silver sulfide dimers. When gold sensitization is used in combination, nuclei consisting of silver sulfide and gold sulfide are formed. Many such chemical sensitization centers are formed in a single silver halide grain. These are initially shallow electron traps that react with interstitial silver ions while capturing electrons to form silver nuclei, which grow to become latent image centers. [See alternative terms] Photographic photosensitivity theory

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

銀塩写真で用いられるハロゲン化銀粒子において，潜像中心が形成されやすい場所をいう．化学増感の一つである硫黄増感が発見された際に，粒子表面に硫化銀核が形成されていると考え，これを感光核と名づけた．のちに，これは硫化銀の二量体であることがわかった．金増感が併用される場合には，硫化銀と硫化金からなる核が形成される．このような化学増感中心は，1個のハロゲン化銀粒子に多数形成される．これらは，はじめ，浅い電子トラップで，電子が捕獲されている間に格子間銀イオンと反応して銀核を形成し，これが成長して潜像中心になる．[別用語参照]写真感光理論

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