Noise Characterization of Midwave Infrared InAs/GaSb Superlattice pin Photodiode

Abstract

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 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu\hbox{m}$</tex></formula> (440 SL periods). This structure exhibits a cut-off wavelength of 4.8 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu\hbox{m}$</tex></formula> at 77 K. Extracted from current–voltage characteristics, zero-bias resistance area product <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${R} _{0}{A}$</tex> </formula> above <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$5\times 10 ^{5} ~\Omega \cdot \hbox{cm}^{2}$</tex></formula> at 80 K was measured. Noise measurements were also performed under dark conditions. The measurements reveal the absence of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$ 1/{f}$</tex></formula> noise above 30 Hz. Moreover, the detector under test remains Schottky noise-limited up to a bias voltage of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$-$</tex></formula> 200 mV typically, which confirms the quality of the MWIR SL pin photodiode.