DETAILED CHARACTERIZATION OF HGCDTE/CDTE MULTIPLE QUANTUM WELLS

We present absorption measurements in HgCdTe/CdTe multiple quantum wells as a function of temperature, polarization, and well size in the 3-4 μm wavelength region. The energy levels are calculated using a model that includes band nonparabolicity. The spectra are fitted to a sum of continuous broadened steps including the two-dimensional Sommerfeld enhancement factor. Polarization measurements confirm the assignment of heavy and light holes. The ratio between heavy and light hole absorption of 2.3/1 agrees well with theory. The fit of the linewidth with temperature shows a homogeneous linewidth of 4.6 meV times the density of longitudinal optical phonons and an inhomogeneous linewidth of 6.4 meV, which is similar to the alloy broadening in the bulk material.