Making a Copper-Oxide Photodetector from Scratch

Photodetectors come in a wide variety of constructions and materials, with the Cu 2 O-based photodetector that [Mad Scientist Creations] demonstrates in a recent video being a good example of a photodetector that can be created at home using nothing but some copper and a heat source. Of the two copper elements in a salt water cell, one element is heated to the point where a copper oxide layer forms, specifically Cu 2 O, which acts as a semiconductor and provides the photosensitive layer.