ZnGeGa2N4

Contents

• Crystal Structures

• Electronic Band Structure

• Synthesis and Growth Methods

• X-Ray Diffraction

ZnGeGa₂N₄

ZnGeGa2N₄ corresponds to the 50 % alloy of ZnGeN₂ and GaN. The question of the degree of ordering in this alloy or whether a separate well-defined ordered compound exists on the convex hull will require further work.

The possibility of ordered octet-rule conserving alloys or compounds was considered in [1]. Disordered alloys were reported by Suehiro et al. [2].

Crystal Structure

Jayatunga et al. [1] reported two possible 16-atom orthorhombic unit cell structures as shown below. They are related to the underlying wurtzite structure and replaced Ge and Zn atoms in the Pbn2₁ structure of ZnGeN₂ by Ga in such a way that each N is bonded to exactly one Zn, one Ge, and two Ga, thus satisfying the octet rule.

Space Group: (a). Pmn2₁ and (b). P1n1

(a) (b)

Figure 1: Octet-rule-preserving ZnGeGa₂N₄structures (a) Pmn2₁ , and (b) P1n1 space groups. Dark-blue spheres: Zn; light-blue: Ge; slightly larger beige: Ga; and small white spheres: N. The dashed horizontal lines indicate the n-type mirror plane, the dash-dotted vertical lines, the m-type mirror plane, and the ovals the twofold screw axes.

Lattice Constants:

Electronic Band Structure

Figure 2: Electronic band structure and partial densities of states for ZnGeGa₂N₄ in the Pmn2₁ structure within the 0.8 sigma approximation

• • Band Gaps :

Synthesis and Growth Methods

• 1. Powder Synthesis of quaternary wurtzitic nitrides in the system ZnGeN₂−GaN for Photocatalytic applications [2]

  2. Metalorganic chemical vapor deposition of ZnGeGa₂N₄

X-Ray Diffraction

Figure 3: Simulated XRD spectra of the GaN, Pmn2₁ and P1n1 ZnGeGa₂N₄, and Pbn2₁ ZnGeN₂

References.

[1]. Jayatunga, B. H. D.; Lyu, S.; Radha, S. K.; Kash, K.; Lambrecht, W. R. L. Physical Review Materials 2018, 2 (11).

[2]. Suehiro, T.; Tansho, M.; Shimizu, T.The Journal of Physical Chemistry C (49), 27590-27596.