AgCl Photolysis: Latent Image Formation

Silver chloride nanocrystals are the working material behind photographic film and AgCl photolithographic masks, and this simulator renders the real mechanism that makes them light-sensitive: the Gurney-Mott model of latent-image formation. A rock-salt AgCl lattice sits at the centre of the scene while photons of a tunable wavelength strike it at a tunable rate. Each photon above the ≈3.25 eV band-gap threshold excites an electron that migrates to one of several sensitivity specks — lattice defects marked on the crystal surface — and reduces an interstitial Ag⁺ ion to metallic Ag⁰, visibly growing a silver cluster at that site. Live readouts track photons absorbed, total silver atoms deposited, the largest cluster, and how many specks have crossed the four-atom stability threshold that makes a cluster permanently developable.