In this study, we have successfully deposited n-type Cu2O triangular nanopyramids on Si by employing ion beam sputter deposition with an Ar : O-2 ratio of 9 : 1 at a substrate temperature of 450 degrees C. Scanning electron microscopy measurements showed attractively triangular nanopyramids of similar to 500 nm edge and height lengths. Both X-ray diffraction and Raman spectroscopy characterizations showed the structures were single-phase polycrystalline Cu2O, and the room-temperature photoluminescence investigation showed interestingly green and blue exciton luminescence emissions. All Mott-Schottky, linear sweep voltammetry, and photocurrent measurements indicated that the conductivity of the Cu2O pyramids is of n-type.