The supplementary material provides a comprehensive analysis of the time-resolved photoluminescence (TRPL) and photoluminescence (PL) characteristics of the CdTe/MgCdTe double heterostructures (DHs) incorporating various passivation materials with an approximate thickness of 0.5 nm. In addition, it includes the calculations of surface recombination velocity (SRV) and recombination current density (J0) for all passivation layers.