Author(s)

Mabrouk Zemzemi, Sahbi Alaya

Laboratory of Physics of Materials and Nanomaterials applied to Environment, Faculty of Sciences of Gabes, University of Gabes, Gabes, Tunisia.

Many materials have been used in nanostructured devices; the goal of attaining high-efficiency thin-film solar cells in such a way has yet to be achieved. Heterojunctions based on ZnO/Cu₂O oxides have recently emerged as promising materials for high-efficiency nanostructured devices. In this work, we are interested in the characterization of the surface and interface through nano-scale modeling based on ab initio (Density Functional Theory (DFT), Local Density Approximation (LDA), Generalized Gradient Approximation (GGA-PBE), and Pseudopotential (PP)). This study aims also to build a supercell containing a ZnO/Cu₂O heterojunction and study the structural properties and the discontinuity of the valence band (band offset) from a semiconductor to an-other. We investigate crystal terminations of ZnO (0001) and Cu₂O (0001). We calculate the energies of the polar surfaces and the work function in the c-axis for both oxides. We built a zinc oxide layer in the wurtzite structure along the [0001] direction, on which we placed a copper oxide layer in the hexagonal structure (CdI₂-type). We choose the method of Van de Walle and Martin to calcu-late the energy offset. This approach fits well with the DFT. Our calculations give us a value that corresponds to other experimental and theoretical values.

Heterojunction, Structure and Electronic Properties, Band Offsets, Surface Energy, Workfunction, Density Functional Theory, Average Potential Method

Zemzemi, M. and Alaya, S. (2015) First Principles Study of the Structural and Electronic Properties of the ZnO/Cu₂O Heterojunction. Materials Sciences and Applications, 6, 661-675. doi: 10.4236/msa.2015.67068.