Hg1−xCdxTe based quantum wells for the 3‐μm wavelength region

HgCdTe multiple quantum wells with transition energies near 3 μm have been grown by molecular‐beam epitaxy. We observe photoluminescence from 2 K to room temperature, and the low‐temperature peak width is consistent with layer thickness fluctuations limited to one monolayer. High‐resolution transmission electron microscopy shows that there is some roughness at the interfaces, but that there is good layer thickness uniformity throughout the structure. The absorption spectra contain sharp, steplike features due to carrier confinement in the wells at energies that can be described by a square‐well model, provided that a temperature‐independent HgTe/CdTe valence‐band offset near 400 meV is assumed.