The effect of pressure on the structural, elastic, electronic, magnetic, and optical properties of Mo-doped ZnSe alloy

Abstract

Abstract We studied the effect of pressure on the structural, elastic, electronic, magnetic, and optical properties of Mo-doped ZnSe alloy based on spin-polarized first-principles calculations using the generalized gradient approximation (GGA) + U and Heyd-Scuseria-Ernzerhof hybrid functional (HSE06) methods. The band gaps for pristine ZnSe compound were 1.152, 1.495, and 2.268 eV using the GGA, GGA + U and HSE06 methods, respectively. The Zn1−xMoxSe (x = 0.03125, 0.0625, and 0.125) alloys were half-metallic (HM) using the GGA + U method which could be used in spintronic devices. The Zn1−xMoxSe (x = 0.50, 0.75, and 1.00) alloys were metallic, and the Zn0.75Mo0.25Se alloy was HM using the GGA + U method. The Zn1−xMoxSe (x = 0.25 and 0.50) alloys were HM, and the Zn1−xMoxSe (x = 0.75 and 1.00) alloys were metallic using the HSE06 method. The spin-down band gap E g and HM band gap E g HM increased with increasing pressure using both the GGA + U and HSE06 methods. For both the GGA + U and HSE06 methods, the peaks of half-occupied t 2g and occupied e g states of Mo atoms shifted to the lower energy region with increasing pressure. The four 4d electrons of Mo2+ ion preponderantly induced the total magnetic moment of 4 μ B /cell. The spin exchange splitting energy Δ x ( d ) decreased, but the absolute value of exchange splitting energy Δ x ( p d ) increased with increasing pressure. The blue shift characteristic of peaks of dielectric constants e 1 ( ω ) and e 2 ( ω ) , refractive index n ( ω ) , extinction coefficient k ( ω ) , and absorption coefficient α ( ω ) with increasing pressure was observed using both the GGA + U and HSE06 methods.