Characterization of midwave infrared InAs/GaSb superlattice photodiode

We report on structural, electrical, and optical characterizations of midwave infrared InAs/GaSb superlattice (SL) p-i-n photodiodes. High-quality SL samples, with 1 mu m thick active region (220 SL periods), exhibited a cut-off wavelength of 4.9 mu m at 80 K. Using a capacitance-voltage measurement technique performed on mesa diode, the residual background concentration in the nonintentionally doped region was determined to be 3 X 10(15) cm(-3) at 80 K. Extracted from current-voltage characteristics, R(0)A products above 4 X 10(5) Omega cm(2) at 80 K were measured, and the quantitative analysis of the J-V curves showed that the dark current density of SL photodiode is dominated by generation-recombination processes. Front-side illuminated photodiodes produced responsivity at 80 K equal to 360 mA/W at 4.5 mu m. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3174439]