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ARTICLE

The GGA-mBJ analysis of Ni modified SrS alloys for magnetic ordering and energy harvesting applications

I. Sajjad^a, U. Parveen¹, H. Al-Ghamdi^b,*, M. Yaseen^a, S. Saleem^a, Nasarullah^a

a Spin-Optoelectronics and Ferro-Thermoelectric (SOFT) Materials and Devices Laboratory, Department of Physics, University of Agriculture, Faisalabad 38040, Pakistan
b Department of Physics, College of Sciences, Princess Nourah bint Abdulrahman University, P. O. Box 84428, Riyadh 11671, Saudi Arabia

* Corresponding Author:

Chalcogenide Letters 2025, 22(9), 829-845. https://doi.org/10.15251/CL.2025.229.829

Received 20 June 2025; Accepted 23 September 2025;

Abstract

Herein, we employed modified Becke-Johson (mBJ) potential based first principles method to investigate the structural, optoelectronic, and magnetic properties of pure SrS and Ni doped Sr_1-xNi_xS alloys at varying doping concentrations. Formation enthalpy analysis predicts thermodynamical stability of resultant alloys. Geometry optimization was performed in order to optimize the super cells to obtain ground state energy state. After confirming their stability, we investigated their magnetic, electronic, and optical attributes. Pure SrS exhibits an indirect band gap of 3.53 eV (which is in good agreement with experiments), while nickel doping in SrS results in lowering the bandgap to the range of visible light absorption. Ni doping also causes the induction of magnetic moment in crystal lattice, transforming the resultant alloys into dilute magnetic semiconductors. The density of state (DOS) analysis revealed that d orbital of dopant Ni is mainly responsible for this magnetic semiconducting character. The magnetization accounts for 2.0 μB (6.25% lightly doped Ni-SrS) up to ~8.0 μB (25% densely doped Ni-SrS). We report ample amount of absorbance of visible light for Ni-SrS systems, which is encouraging for future prospects. Moreover, for thermoelectric device applications, the figure of merit (ZT~0.75) plots for densely (25%) Ni doped SrS show higher values at elevated temperatures. Overall, results suggest that Sr_1-xNi_xS alloys are promising candidate for applications in the field of thermoelectric generators, optical absorbers, solar cells, and spintronic devices.

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