It is shown that the properties of sprayed (Cd, Zn)S layers obtained by means of a pneumatic nozzle depend dramatically on the type of flow gas used (air or nitrogen). The role of chemisorbed oxygen is demonstrated. Independently of the various heat treatments applied the resulting CuxS obtained has always a coefficient x closer to 2 when the flow gas is nitrogen. A subsequent annealing of the (Cd, Zn)S layers is found to increase the CuxS growth speed.
It is also shown that the quality of (Cd, Zn)S layers determines to a great extent that of the cuprous sulfide in (Cd, Zn)S-CuxS heterojunctions. The data are interpreted in terms of the modification of the layers structure, composition and charge carrier concentration.