WurtzitStruktur

Wurtzite is a crystal structure named after the mineral wurtzite, which is a form of zinc sulfide (ZnS). It is one of the two common polytypes of zinc sulfide, the other being zincblende. The wurtzite structure is a hexagonal crystal system.

In the wurtzite structure, atoms are arranged in a hexagonal close-packed (HCP) lattice. Each zinc atom is tetrahedrally bonded to four sulfur atoms, and conversely, each sulfur atom is tetrahedrally bonded to four zinc atoms. This tetrahedral coordination is a key feature of the wurtzite structure.

The arrangement of atoms in wurtzite can be described as alternating layers of zinc and sulfur atoms. Within each layer, the atoms form a hexagonal pattern. The stacking sequence of these layers along the c-axis gives rise to the hexagonal symmetry. Specifically, it can be represented as ABAB... stacking, where A and B represent different types of atomic layers.

While chemically similar to the zincblende structure, the stacking sequence differs. Zincblende has a cubic close-packed (CCP) lattice with an ABCABC... stacking sequence. This difference in stacking leads to different symmetry and physical properties, although the local tetrahedral coordination is the same in both structures.

Wurtzite and zincblende are often referred to as polytypes because they have the same chemical composition but differ in their crystal structure due to variations in the stacking of atomic layers. Many compound semiconductors, particularly those with the formula AB (where A is a group II element and B is a group VI element, or similar combinations), can crystallize in either the wurtzite or zincblende structure depending on growth conditions. Examples include GaN, AlN, and ZnO, which commonly adopt the wurtzite structure.