Patent ID: 8734681

Claim:
A luminescent material having the formula: [A a Sn b X x X′ x′ X″ x″ ] wherein the luminescent material is polycrystalline; A is included in the luminescent material as a monovalent cation; X, X′, and X″ are selected from fluorine, chlorine, bromine, and iodine; a is in the range of 1 to 5; b is in the range of 1 to 3; a sum of x, x′, and x″ is in the range of 1 to 5; and at least X′ is iodine, such that x′/(x+x′+x″)≧⅕, wherein the luminescent material includes a dopant selected from at least one of O −2 and OH −1 .