The cuprous oxide(Cu

2

O)films were electrochemically deposited on ITO substrates. The effects of coordination reagents

deposition potentials and pH values on the structure and properties of Cu

2

O were examined. The results show that Cu

2

O films deposited from the electrolyte with lactic acid as the coordination reagent have larger grain size

better crystallinity and higher density

compared with those deposited from the electrolyte with TEA as the coordination reagent. Moreover

in the presence of lactic acid

the nucleation density increases

the grain size decreases and the density rises with an increase in the deposition potential. The preferential orientation of the deposited films changes from(200)to(111)as the pH value rises. In addition

Mott-Schottky plot and the optical transimittance sp

ectrum show that this prepared Cu

2

O film is a p-type semiconductor with a bandgap energy of 1.93 eV.