What is the role of silver iodide

What is the role of silver iodide? There may be a lot of people who haven't seen it, and here's the introduction:

Silver iodide as the bright yellow micro crystalline powder, odourless, which has two kinds of alpha and beta type, type of alpha for cubic crystal, 6.010 g/cm3 density, melting point 558 ℃, boiling point of 1506 ℃. Beta type for the six-party crystal, density 5.683 g/cm3, heated to 146 ℃ or to the type. Insoluble in dilute acid. Water, slightly soluble in ammonia water, easy to dissolve in potassium iodide, potassium cyanide, sodium thiosulfate and methylamine, no matter the solid or the liquid silver iodide, all have the characteristic, can feel from ultraviolet to about 480 mm wavelength of the light. The "silver core", which breaks down into tiny particles, becomes green and gray. Heated with ammonia, the crystallized silver iodide is converted to white.

Silver iodide and silver bromide are mixed to make photographic emulsion. In artificial rainfall, as an ice nucleating agent; They can also protect against hail, frost, snow and storms. It can be used as the raw material for thermoelectric batteries. Used as a catalyst in chemical reactions. It's also used in the medical industry.