Measurement of recombination mechanisms in mid-infrared W-superlattices

Mid-wave infrared LEDs based on 6.1 angstrom III/V semiconductors have trailed well behind visible LEDs in their wallplug efficiency. One contributing inefficiency is the low internal quantum efficiency (IQE) of emission of such materials, which is attributable to dominating nonradiative Auger and Shockley-Read-Hall recombination. However, recent work within this group has identified a W-superlattice based on 6.1 angstrom III/V semiconductors with a remarkably high IQE of 77% (8%) at 77K (300K). We present in this work two-color pump-probe, differential transmission measurements to measure the ABC recombination coefficients of this superlattice at both 77K and 300K to elucidate physical mechanisms.

Automated summary

Mid-wave infrared LEDs based on 6.1 angstrom III/V semiconductors have lower efficiency compared to visible LEDs due to low internal quantum efficiency. Recent research has identified a W-superlattice based on 6.1 angstrom III/V semiconductors with remarkably high IQE at both low and room temperatures. In this work, two-color pump-probe, differential transmission measurements were conducted to study the physical mechanisms of this superlattice.