Disclosed is at least one embodiment of an infrared (IR) photovoltaic (PV) detector, comprising a IV-VI Lead (Pb)-salt layer disposed on a substrate and a charge-separation-junction (CSJ) structure associated with the IV-VI Pb-salt layer, wherein the CSJ structure comprises a plurality of element areas disposed upon or within the IV-VI Pb-salt layer, wherein the plurality of element areas are spaced apart from each other. Each element area may be connected to a first Ohmic contact thereby forming a plurality of interconnected first Ohmic contacts, and a second Ohmic contact may be disposed upon a portion of the IV-VI Pb-salt layer. In another non-limiting embodiment, a PV detector, comprising a heterojunction region that comprises at least one IV-VI Pb-salt material layer coupled to at least one non-Pb-salt layer, wherein the at least one IV-VI Pb-salt layer and the at least one non-Pb-salt layer form a p-n junction or Schottky junction with a type II band gap alignment.