Strain-engineering enables reversible semiconductor–metal transition of skutterudite IrAs₃

Strain engineering is a more effective and green method to achieve the nonmetal-to-metal transition than metal doping. The elastic strain field can effectively change the atomic orbital interaction, achieving the metallization of materials. Taking IrAs₃ as a prototype, the strain–stress behaviors of binary skutterudite are investigated. A reversible semiconductor-to-metal (SM) transition can be easily achieved by only an ∼9% strain. The strain-induced Jahn–Teller effect of IrAs₆ octahedra and the breakage of As₄-rings dominate the metallization. Unexpectedly, the metal element Ir in IrAs₃ becomes an electron acceptor due to its higher electronegativity and the effect of the octahedral field.