Herein,　through　the　analysis　of　devices　with　different　passivation　pretreatment　processes,　it　is　found　that　after　surface　corrosion,　the　optimized　process　of　O3　treatment　combined　with　hydrochloric　acid　and　H3PO4/C6H8O7/H2O2/H2O　treatments　can　significantly　improve　the　electrical　performance　of　the　device.　By　analyzing　the　curves　of　dark　current　density　varying　with　temperature　of　the　mid-wavelength　(MW)　and　long-wavelength　(LW)　dual-color　devices,　it　is　verified　that　there　are　three　leakage　mechanisms　in　the　device:　diffusion　current,　trap-assisted　tunneling　current,　and　generation-recombination　current.　Finally,　a　640　x　512　MW/LW　dual-color　superlattice　infrared　detector　is　fabricated　with　a　pixel　pitch　of　20　mu　m.　The　cutoff　wavelength　of　the　MW　channel　is　5.04　mu　m.　The　cutoff　wavelength　of　the　LW　channel　is　9.51　mu　m.　The　noise　equivalent　temperature　difference　of　MW　is　16.5　mK　and　LW　is　35.1　mK.　The　photoresponse　nonuniformity　is　6.21%　for　MW　and　10.51%　for　LW.　The　blind　pixel　rate　is　0.66%　for　MW　and　8.56%　for　LW.　The　imaging　demonstration　is　completed.　The　research　has　laid　the　foundation　for　the　engineering　application　of　dual-color　infrared　detectors.　This　work　first　studies　passivation　pretreatment　processes,　finding　that　an　optimized　process　combining　O3　treatment,　HCl,　and　H3PO4/C6H8O7/H2O2/H2O　treatment　after　surface　mesa　can　significantly　improve　electrical　performance.　The　dark　current　mechanisms　are　then　studied　through　temperature-dependent　measurements.　Finally,　a　640　x　512　mid-wavelength/long-wavelength　dual-color　superlattice　infrared　detector　is　fabricated　and　characterized.image　(c)　2024　WILEY-VCH　GmbH