Photo-conducting infrared sensors are provided including a substrate (e.g., silicon) with one or more trenches formed on a first surface. An infrared-reflective film can be deposited directly or indirectly onto and conforming in shape with the first surface of the substrate. A lead chalcogenide film can be deposited directly or indirectly over the top of the infrared-reflective film and conforming in shape with the first surface of the substrate. Accordingly, the infrared-reflective film is directly or indirectly sandwiched between the substrate and the lead chalcogenide film.