AgCl Photolysis: Latent Image Formation (2D)

Silver chloride nanocrystals are the working material behind photographic film and AgCl photolithographic masks, and this 2D array simulator renders the real statistical mechanism that makes them light-sensitive: the Gurney-Mott model of latent-image formation, played out across dozens of grains at once. Photons of a tunable wavelength strike the array at a tunable per-grain rate; each photon above the ≈3.25 eV band-gap threshold is absorbed by one randomly chosen grain, exciting an electron that migrates to one of that grain's sensitivity specks and reduces an interstitial Ag⁺ ion to metallic Ag⁰. A grain only crosses into "developable" once a single speck accumulates four Ag⁰ atoms — photons scattered across different specks in the same grain never form a stable cluster and that grain stays undeveloped, even after absorbing several photons. Live readouts and a running graph track how the developable fraction of the array climbs with exposure, a genuinely non-linear curve driven by real clustering statistics rather than a simple photon count.