The Copper Oxide with Alkali Potassium Dopant for Heterojunction Solar Cells Application

This work aimed to produce a low resistive copper oxide nanolayer with potassium admixture by a simple spray coating technique. The different concentration of dopant (2–20 wt%) was tested. It was found that 14 wt% of potassium reduced the resistivity of copper oxide from 21 Ω cm for reference layer to 5 Ω cm for doped thin film. The phase composition as well as the optical, and electrical properties of manufactured oxides were studied. It was found that potassium admixture affects the phase composition of manufactured thin film which turns from CuO to Cu₂O. This is accompanied by a widening of the optical band gap energy of the oxide. The roughness of the layer also increased. The photovoltaic properties of produced copper oxides were tested in n–i–p heterojunction with n-type Cz-Si and as a final product the solar cells with open circuit voltage of 296 mV and short circuit current density of 0.78 mA/cm² was fabricated.