The present disclosure discloses, in one arrangement, a single crystalline iodide scintillator material having a composition of the formula AM1−xEuxI3, A3M1−xEuxI5 and AM2(1−x)Eu2xI5, wherein A consists essentially of any alkali metal element (such as Li, Na K, Rb, Cs) or any combination thereof, M consists essentially of Sr, Ca, Ba or any combination thereof, and 0≦x≦1. In another arrangement, the above single crystalline iodide scintillator material can be made by first synthesizing a compound of the above composition and then forming a single crystal from the synthesized compound by, for example, the Vertical Gradient Freeze method. Applications of the iodide scintillator materials include radiation detectors and their use in medical and security imaging.