HgCdTe Tunable-Bandgap Infrared Detector

Mercury cadmium telluride (Hg_1-xCd_xTe) is the workhorse alloy of cooled infrared imaging: by dialing the cadmium fraction x during crystal growth, engineers set the semiconductor bandgap — and therefore the infrared cutoff wavelength — anywhere from the short-wave band out past 14 microns. This simulator renders a real 3D zinc-blende nanocrystal lattice whose cation sites shift between mercury (cyan) and cadmium (gold) as you move the composition slider, computes the true bandgap from the empirical Hansen formula used in detector design, and lets you fire individual photons — or auto-scan across wavelength — to watch absorption switch on exactly at the predicted cutoff.