Copper zinc oxide: Investigation into a p-type mixed metal oxide system

Alloying ZnO with CuO gave a range of p-type films with varying electrical, optical and structural characteristics. XRD patterns show that as copper content was increased above 24.5% of the total metal content, crystal structure changed from a typical ZnO wurtzite structure to a CuO tenorite structure. A second change occured at 35% copper with the emergence of two further tenorite peaks. These structural changes correlate to significant local increases in band-gap, visible and infrared transmission, and resistivity. These dramatic changes correspond to relatively minor compositional variations. Through careful control of the alloy composition it is therefore theoretically possible to tailor the material properties to suit a wide range of applications, both in photovoltaics and in other fields.