摘要
Hydrostatic pressure provides an efficient way to tune and optimize the properties of solid materials without chang-ing their composition.In this work,we investigate the electronic,optical,and mechanical properties of antiperovskite X_(3)NP(X^(2+)=Ca,Mg)upon compression by first-principles calculations.Our results reveal that the system is anisotropic,and the lat-tice constant a of X_(3)NP exhibits the fastest rate of decrease upon compression among the three directions,which is different from the typical Pnma phase of halide and chalcogenide perovskites.Meanwhile,Ca_(3)NP has higher compressibility than Mg_(3)NP due to its small bulk modulus.The electronic and optical properties of Mg_(3)NP show small fluctuations upon compression,but those of Ca_(3)NP are more sensitive to pressure due to its higher compressibility and lower unoccupied 3d orbital energy.For example,the band gap,lattice dielectric constant,and exciton binding energy of Ca_(3)NP decrease rapidly as the pressure increases.In addition,the increase in pressure significantly improves the optical absorption and theoretical conversion effi-ciency of Ca_(3)NP.Finally,the mechanical properties of X_(3)NP are also increased upon compression due to the reduction in bond length,while inducing a brittle-to-ductile transition.Our research provides theoretical guidance and insights for future experi-mental tuning of the physical properties of antiperovskite semiconductors by pressure.
基金
supported by the Science and Technology Research Program of Chongqing Municipal Education Commission (Grant No. KJQN202100626)
the Science and Technology Research Program of Chongqing Municipal Education Commission (Grant No. KJQN202200619)
supported by Beijing Institute of Technology Research Fund Program for Young Scholars (Grant No. XSQD-202222008)
the support from the National Natural Science Foundation of China (Grant No. 12204081)
the Natural Science Foundation of Chongqing (Grant No. 2022NSCQ-MSX2540)
supported by TianHe Qingsuo Project-spec ial fund project
