Abstract

Narrow-gap antimonide-based semiconductors provide great flexibility for band engineering with their bandgap being adjustable in a wide range to achieve emission in the mid-wave infrared spectral region (λ ~3-5 m). Despite the rapid development of light-emitting diode (LED) technology over the last few years, the poor extraction efficiency severely limits the device power performance in the mid-infrared region. The large difference in refractive index between the narrow-gap semiconductor material (n ≥ 3.5) and the surrounding medium (typically air) results in a large portion of the light being trapped within the device through total internal reflection and Fresnel reflection, thus limiting the light extraction efficiency to a few percents [1].

© 2013 IEEE