Insights about AlP (001) Surface Reconstructions: A Density Functional Theory Study

Using first-principles calculations and thermodynamics criteria, we investigated the structural and electronic properties of the AlP (001) surface. We considered 18 different possible surface reconstructions. They were chosen by considering the stable surfaces reported for other III–V semiconductors. According to the results, five stable surface reconstructions were found: at Al-rich conditions, the (2 × 4) mixed dimer and the δ (2 × 6) surfaces, at intermediate conditions, the δ (2 × 4), and β2 (2 × 4) surface reconstructions, and at P-rich conditions, the (2 × 2) P-dimer. Electronic properties were evaluated by calculating the density of states. The results show that the surfaces have semiconductor behavior, except for the (2 × 2) P-dimer, which is metal. Electron localization function (ELF) line profiles demonstrate the covalent nature of the Al–P and P–P bonds, while the Al–Al interaction is metallic. Our results provide insights into the possible surface reconstructions in the AlP compounds. Also, the results suggest that the surfaces are good candidates to be employed in the development of diluted magnetic semiconductors.