Mercuric iodide in prospective

•We review the growth of mercuric iodide crystals.•We review advances in detector design and application.•We provide an outlook on the interest in mercuric iodide for special applications as semiconductor detectors.

We present a review on mercuric iodide technology for room temperature gamma radiation detection. After four decades of research and development the material is attractive for a number of applications for x-ray and gamma-ray imagers with performances that match all competing materials. The crystal growth of large single crystals is challenging; however the high resistivity of 1013 Ω cm, the undoped, as-grown crystals and the high radiation damage remaining features that are not exhibited by any other wide bandgap semiconductor materials.