Wide-bandgap semiconductor of three-dimensional unconventional stoichiometric NaCl2 crystal

TL;DR

This paper reports the discovery and synthesis of a novel wide-bandgap NaCl2 crystal, achieved through unconventional stoichiometry, with potential applications in electronics and materials science.

Contribution

The study introduces a new wide-bandgap semiconductor NaCl2 crystal, synthesized under ambient conditions, based on a novel stoichiometric design strategy that breaks traditional frameworks.

Findings

NaCl2 crystal is a wide-bandgap semiconductor with 2.24 to 4.45 eV bandgap.

Successful synthesis of NaCl2 crystal under ambient conditions.

Unconventional stoichiometry enables bandgap tuning and potential discovery of other functional materials.

Abstract

The expanding applications call for novel new-generation wide-bandgap semiconductors. Here, we show that a compound only composed of the ordinary elements Na and Cl, namely three-dimensional NaCl2 crystal, is a wide-bandgap semiconductor. This finding benefits from the breaking of conventional stoichiometry frameworks in the theoretical design, leading to the discovery of three-dimensional XY2 (X = Na, Li, K; Y = Cl, F, Br, I) crystals, with covalent bonds of Y pairs inducing the wide bandgap from 2.24 to 4.45 eV. Crucially, such an unexpected NaCl2 crystal was successfully synthesized under ambient conditions. The unconventional stoichiometric strategy with other chemical elements potentially yields more wide-bandgap semiconductors, offering the capability for bandgap tuning. These unconventional stoichiometric materials may also exhibit superconductivity, transparent inorganic electrides, high-energy-density, and beyond.