Pengaruh Doping Pb Pada Struktur Pita Dan Konduktivitas Perovskit MASn1-xPbxI3 (x = 0; 0,5) : Studi Simulasi Dengan DFT

Romadona, Dewanti (2026) Pengaruh Doping Pb Pada Struktur Pita Dan Konduktivitas Perovskit MASn1-xPbxI3 (x = 0; 0,5) : Studi Simulasi Dengan DFT. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Perovskit hibrida berbasis timah (Sn) merupakan material fotovoltaik yang berpotensi menggantikan perovskit berbasis timbal (Pb), tetapi memiliki kendala stabilitas akibat oksidasi Sn²⁺ menjadi Sn⁴⁺. Salah satu upaya untuk meningkatkan stabilitas material adalah melalui substitusi sebagian atom Sn dengan Pb. Penelitian ini bertujuan menganalisis pengaruh doping Pb terhadap struktur kristal, struktur pita energi, Partial Density of States (PDOS), dan sifat elektronik MASn₁₋ₓPbₓI₃ (x = 0 dan 0,5) menggunakan metode Density Functional Theory (DFT). Simulasi dilakukan melalui optimasi geometri, perhitungan struktur pita energi, dan analisis PDOS menggunakan perangkat lunak Quantum ESPRESSO dengan pendekatan Generalized Gradient Approximation Perdew Burke Ernzerhof (GGA-PBE). Hasil menunjukkan bahwa substitusi Pb tidak mengubah kerangka dasar struktur perovskit, tetapi menyebabkan perubahan parameter kisi dan distorsi lokal setelah relaksasi. Perubahan tersebut memengaruhi interaksi orbital Sn/Pb dan I sehingga mengubah struktur pita energi serta sifat elektronik material. MASnI₃ memiliki direct band gap sebesar 0,31 eV, sedangkan substitusi Pb pada MA(Sn₀.₅Pb₀.₅)I₃ menurunkan band gap dan mengubah distribusi pita energi di sekitar tingkat Fermi. Analisis PDOS menunjukkan bahwa pita valensi didominasi orbital p atom I, sedangkan pita konduksi didominasi orbital p atom Sn dan Pb. Secara keseluruhan, doping Pb memodifikasi sifat elektronik material tanpa mengubah struktur dasar perovskit serta berpotensi meningkatkan karakteristik transport pembawa muatan.
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Tin (Sn)-based hybrid perovskites are promising photovoltaic materials as alternatives to lead (Pb)-based perovskites, but their practical application is limited by poor stability due to the oxidation of Sn²⁺ to Sn⁴⁺. One strategy to improve their stability is the partial substitution of Sn with Pb. This study aims to investigate the effect of Pb doping on the crystal structure, band structure, Partial Density of States (PDOS), and electronic properties of MASn₁₋ₓPbₓI₃ (x = 0 and 0.5) using Density Functional Theory (DFT). Geometry optimization, band structure calculations, and PDOS analysis were performed using Quantum ESPRESSO with the Generalized Gradient Approximation Perdew Burke Ernzerhof (GGA-PBE) approach. The results indicate that Pb substitution preserves the fundamental perovskite framework while inducing changes in lattice parameters and local structural distortion after relaxation. These structural modifications affect the orbital interactions between Sn/Pb and I atoms, leading to changes in the band structure and electronic properties. MASnI₃ exhibits a direct band gap of 0.31 eV, whereas Pb substitution in MA(Sn₀.₅Pb₀.₅)I₃ reduces the band gap and modifies the energy band distribution near the Fermi level. PDOS analysis reveals that the valence band is dominated by I-p orbitals, while the conduction band is mainly contributed by Sn-p and Pb-p orbitals. Overall, Pb doping effectively modifies the electronic properties while preserving the perovskite framework and has the potential to enhance charge carrier transport characteristics.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Density Functional Theory (DFT), Doping Pb, Partial Density of States (PDOS), Perovskit, Struktur Pita Energi. Band Structure; Density Functional Theory (DFT); Partial Density of States (PDOS); Pb Doping; Perovskite.
Subjects:	Q Science Q Science > QC Physics > QC100 Crystals. Q Science > QC Physics > QC451 Spectroscopy Q Science > QC Physics > QC585 Dielectrics Q Science > QC Physics > QC610.3 Electric conductivity
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Physics > 45201-(S1) Undergraduate Thesis
Depositing User:	Dewanti Nur Romadona
Date Deposited:	05 Aug 2026 01:32
Last Modified:	05 Aug 2026 01:32
URI:	http://repository.its.ac.id/id/eprint/143876

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