Preparation Of P-type Cu₂O Thin Films By DC Magnetron Sputtering

As the ever increasing consumption of oil, coal and other traditional energy resources, renewable and low cost solar energy is attracting more and more attentions internationally. With the further research into the new solar cells-thin film solar cells, to fabricate high quality and low cost solar energy films is a most straight approach.Cu₂O thin films has the energy bandgap of about 2.0-2.5eV, which matches the solar spectra and has a high theoretical photovoltaic conversion efficiency. Other merits of Cu₂O include low cost, nontoxic, abundant raw materials, no pollution and high stability. But CuO with a narrower bandgap and n-type conduction usually presents in p-type Cu₂O films, which will influence the photovoltaic conversion efficiency. So how to prepare pure p-type Cu₂O is a very of importance if Cu₂O films are to be used in solar cells.In this thesis, the preparation technology, property, application in solar cells of the p-type Cu₂O thin films, and the ways to improve the Cu₂O properties are introduced. Firstly, Cu₂O films were prepared by reactive magnetron sputtering, then quantum density function theory based on the first principle calculation was performed for nitrogen doped Cu₂O:N, and the results showed that substitutional N is a shallow acceptor in Cu₂O. By this prediction, Cu₂O:N thin films were prepared by two ways, and pure Cu₂O phase films with hole concentration as high as 3.99×10¹⁹cm^-3 and resistivity as low as 1.21Ω·cm was prepared.