Noise Characterization of Midwave Infrared InAs/GaSb Superlattice pin Photodiode

We report on noise characterization of a midwave infrared (MWIR) InAs/GaSb superlattice (SL) single detector. The SL structure was made of eight InAs monolayers (MLs) and eight GaSb MLs, with a total thickness of 2 μm (440 SL periods). This structure exhibits a cut-off wavelength of 4.8 μm at 77 K. Extracted from current-voltage characteristics, zero-bias resistance area product R₀ A above 5×10⁵ Ω · cm² at 80 K was measured. Noise measurements were also performed under dark conditions. The measurements reveal the absence of 1/f noise above 30 Hz. Moreover, the detector under test remains Schottky noise-limited up to a bias voltage of -200 mV typically, which confirms the quality of the MWIR SL pin photodiode.