III-V semiconductor mid-infrared interband cascade light emitters and detectors

We present recent work on III-V semiconductor mid-infrared light emitters and detectors. The employed type-II broken bandgap alignment between InAs and GaxIn1-xSb allows for widely tunable emission and absorption wavelengths with energies below the individual material bandgaps. We demonstrate room temperature operation of GaSb-based interband cascade lasers (ICLs) emitting between 6.1 and 6.9 μm. Furthermore, we investigate ideal growth conditions for InAs/GaSb type-II superlattices (T2SL) for the implementation in interband cascade detectors (ICDs) with cut-off wavelengths up to 7.5 μm at room temperature. We focus on strain balancing different SL compositions for different cutoff wavelengths via Sb-soak and sub-monolayer (SML) growth of InSb. An ideal growth temperature of TSub=430 °C is found by comparing the quality of different sets of samples by means of high-resolution X-ray diffractometry (HRXRD) and room temperature photoluminescence (PL) measurements.