A Map of the Zintl AM2Pn2 Compounds: Influence of Chemistry on Stability and Electronic Structure
arXiv:2502.08801 · doi:10.1021/acs.chemmater.5c00353
Abstract
The AM2Pn2 (A= Ca, Sr, Ba, Yb, Mg; M= Mn, Zn, Cd, Mg; and Pn=N, P, As, Sb, Bi) family of Zintl phases has been known as thermoelectric materials and has recently gained much attention for highly promising materials for solar absorbers in single junction and tandem solar cells. In this paper we will, from first-principles, explore the entire family of AM2Pn2 compounds in terms of their ground state structure, thermodynamic stability, and electronic structure. We also perform photoluminescence spectroscopy on bulk powder and thin film samples to verify our results, including the first measurements of the bandgaps of SrCd2P2 and CaCd2P2. The AM2Pn2 compounds exhibit broad stability, are mostly isostructural in the CaAl2Si2-type structure (P3m1), and cover a wide range of bandgaps from 0 to beyond 3 eV. This could make them useful for a variety of purposes, for which we propose several candidates, such as CaZn2N2 for tandem top cell solar absorbers and SrCd2Sb2 and CaZn2Sb2 for infrared detectors. By examining the band structures of the AM2Pn2, we find that Mg3Sb2 has the most promise as a thermoelectric material due to several off-Γ valence band pockets which are unique to it among the compositions studied here.
46 pages, 12 figures, submitted to Chemistry of Materials
References in corpus (6)
- Spin fluctuation induced Weyl semimetal state in the paramagnetic phase of EuCdAs
- Indirect band gap semiconductors for thin-film photovoltaics: High-throughput calculation of phonon-assisted absorption
- Magnetic, thermal, and electronic-transport properties of EuMg2Bi2 single crystals
- Discovery of the Zintl-phosphide BaCdP as a long carrier lifetime and stable solar absorber
- Dipolar Magnetic Interactions and A-type Antiferromagnetic Order in the Zintl Phase Insulator EuZn2P2
- A-type antiferromagnetic order in semiconducting EuMgSb single crystals