Modeling the structure of an oxide solar cell
The article discusses numerical simulation of an oxide solar cell based on a Cu<sub>2</sub>O/TiO<sub>2</sub> p-n heterojunction was carried out to optimize its structure and increase the efficiency of energy conversion. The influence of layer thicknesses, concentrations of acceptors and donors in Cu<sub>2</sub>O and TiO<sub>2</sub> layers, as well as the work function of the back contact material on the photoelectric parameters of the solar cell is studied. It was found that the optimal thickness of Cu<sub>2</sub>O and TiO<sub>2</sub> layers is 1.5 µm and 100 nm, respectively. It is shown that to obtain a high efficiency of a solar cell, the concentration of acceptors in the Cu<sub>2</sub>O layer should be 10<sup>16</sup> cm<sup>-3</sup>, and the concentration of donors in the TiO<sub>2</sub> layer should be 10<sup>19</sup> cm<sup>-3</sup>. It has been found that the work function of the back contact material must be at least 4.9-5 eV in order to achieve high efficiency values. The most suitable contact materials for Cu<sub>2</sub>O are Ni, C and Cu. For a solar cell based on a Cu<sub>2</sub>O/TiO<sub>2</sub> p-n heterojunction, a maximum efficiency of 10.21 % was obtained (short circuit current density 9.89 mA/cm<sup>2</sup>, open circuit voltage 1.38 V, fill factor 74.81 %). The results can be used in the development and formation of heterostructures of inexpensive oxide solar cells.