Global Journal of Engineering and Technology Research (GJETR)

Density Functional Theory Investigation of Defect-Induced Electronic Behavior in Iodine-Deficient Mapbi₃ Perovskites for Solar Cells

Kado, Sani, Onimisi, Muhammad Y., Sanni, Dahiru M.

30 September 2026 · Vol. 2, Issue 9, pp. 579-585

DOI: 10.65150/EP-gjetr/V2E9/2026-15

Abstract

This work Demonstrated a Density Functional Theory (DFT) investigation of the electronic properties and iodine vacancy defects in methylammonium lead iodide (MAPbI₃) using the Vienna Ab initio Simulation Package (VASP). We analyzed the structural and electronic properties of both pristine and defective MAPbI₃ systems. Density of state (DOS) and band structure calculations confirmed that pristine MAPbI₃ is a direct-bandgap semiconductor. Our defect analysis revealed that iodine vacancies alter the electronic structure by introducing new states near the band edges. Formation energy calculations showed that the positively charged iodine vacancy (+1) possesses the lowest formation energy (0.20 eV), indicating its thermodynamic stability. The values of Charge transition levels for ε (+1/0), and ε (0/−1) were obtained as 1.12 eV and 1.52 eV respectively within the bandgap. The defect concentration analysis showed that the +1-charge state is the most stable and predominant at both 298 K and 333 K. This indicates that iodine vacancies play an important role in determining the charge transport and recombination behavior of MAPbI₃. Understanding these defect effects provides useful insight for optimizing the material properties and enhancing the efficiency and overall performance of perovskite solar cells.

Keywords: Density Functional Theory, MAPbI, iodine vacancy, perovskite solar cells, VASP, defect formation energy

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Kado, Sani, Onimisi, Muhammad Y., Sanni, & Dahiru M. (2026). Density Functional Theory Investigation of Defect-Induced Electronic Behavior in Iodine-Deficient Mapbi₃ Perovskites for Solar Cells. Global Journal of Engineering and Technology Research, 2(9), 579-585. https://doi.org/10.65150/EP-gjetr/V2E9/2026-15

@article{Kado2026,
  title   = {Density Functional Theory Investigation of Defect-Induced Electronic Behavior in Iodine-Deficient Mapbi₃ Perovskites for Solar Cells},
  author  = {Kado and Sani and Onimisi and Muhammad Y. and Sanni and Dahiru M.},
  journal = {Global Journal of Engineering and Technology Research},
  year    = {2026},
  volume  = {2},
  number  = {9},
  pages   = {579-585},
  doi     = {10.65150/EP-gjetr/V2E9/2026-15},
  url     = {https://doi.org/10.65150/EP-gjetr/V2E9/2026-15}
}

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