Performance of mid-wave infrared (3.8 μm) light emitting diode device

We describe the temperature-dependent characteristics of light emission from an IR interband cascade (IC) Type II-superlattice light emitting diode (LED) structure, which is mounted epi-side down. Light, current, and voltage (LIV) curves and spectra are reported for CW and pulsed excitation at various temperatures. At room temperature, we observe a typical increase in light and voltage with increasing CW current. At lower temperatures, as the CW excitation current is progressively increased to greater values, the LED emission peaks, followed by a power decrease, and finally approaches values similar to that of the room temperature emission. The room temperature CW peak power is 28% of the peak at liquid helium temperature. The LI results and spectra for pulsed excitation are compared. We observed red and blue shifts in peak emission wavelength with increasing current for CW and pulsed operation, respectively.