Mid-wave T2SLs InAs/GaSb single pixel PIN detector with GaAs immersion lens for HOT condition

In this paper we report on high operating temperature mid-wave infrared detector based on type-II superlattice InAs/GaSb mesa PIN architecture with 50% cut-off wavelength ∼5.2 μm at 230 K. The 1.1 mm thick GaAs substrate was converted into immersion lens to limit an influence of the defects occurring during growth on GaAs substrate and to increase detectivity, ∼2 × 10¹⁰ cm Hz^1/2/W at 230 K, under reverse bias 100 mV and ∼4 × 10⁹ cm Hz^1/2/W at 300 K, under 500 mV. Presented results are better than PIN architectures with the same and lower cut-off wavelength grown on GaAs without immersion lens and grown on GaSb substrates.