Studi Komputasi Sifat Elektronik dan Optik Polimorf MoS2 berbasis Teori Fungsional Kerapatan

Mukaromah, Fadilah Siti (2026) Studi Komputasi Sifat Elektronik dan Optik Polimorf MoS2 berbasis Teori Fungsional Kerapatan. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Molybdenum Disulfide (MoS2) merupakan material dua dimensi yang mendapat perhatian luas karena sifat optoelektronik dan katalitiknya yang unggul dengan performa material ini bergantung pada konfigurasi struktur kristalnya. Studi ini bertujuan untuk menginvestigasi dan membandingkan secara komprehensif sifat elektronik dan respons optik dari tiga polimorf utama MoS2, yaitu fasa 2H, 1T, dan 3R dalam wujud bulk yang dilakukan secara komputasifirst-principles menggunakan metode Density Functional Theory (DFT) pada perangkat lunak Quantum ESPRESSO. Evaluasi properti diekstraksi pasca-optimasi geometri melalui kalkulasiSelf-Consistent Field (SCF) dan Non-Self Consistent Field (NSCF) menggunakan kombinasi pseudopotensial Projector Augmented Wave (PAW) dan Norm-Conserving. Hasil perhitungan struktur pita energi dan Density of States (DOS) mengonfirmasi bahwa fasa 2H dan 3R merupakan semikonduktor dengan celah pita tidak langsung masing-masing sebesar 1,34 eV dan 1,36 eV, dengan elektron valensi yang terlokalisasi kuat secara statis. Sebaliknya, fasa 1T terkonfirmasi metalik (celah pita 0 eV) akibat delokalisasi elektron secara masif. Karakteristik ini sejalan dengan respons optiknya yakni fasa 2H dan 3R transparan pada energi rendah dan menyerap efektif spektrum cahaya tampak hingga ultraviolet. Sementara fasa 1T menunjukkan perilaku optik logam ideal dengan lonjakan ekstrem pada fungsi dielektrik imajiner di energi foton mendekati nol dan reflektansi yang sangat tinggi di wilayah inframerah. Melalui komparasi ketiga fase ini, penelitian ini diharapkan memberikan landasan teoretis yang kuat mengenai interaksi struktur-properti pada MoS2 sekaligus memberikan panduan prediktif bagi rekayasa material lanjutan.
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Molybdenum Disulfide (MoS2) is a two-dimensional material that has garnered widespread attention due to its superior optoelectronic and catalytic properties, with its performance heavily dependent on its crystal structure configuration. This study aims to comprehensively investigate and compare the electronic properties and optical responses of the three main polymorphs of MoS2 namely the 2H, 1T, and 3R phases in bulk form conducted via first-principles computational modeling using Density Functional Theory (DFT) in the Quantum ESPRESSO software. Property evaluations were extracted post-geometry optimization through Self-Consistent Field (SCF) and Non-Self Consistent Field (NSCF) calculations, utilizing a combination of Projector Augmented Wave (PAW) and Norm-Conserving pseudopotentials.The calculation results of the energy band structures and Density of States (DOS) confirm that the 2H and 3R phases are semiconductors with indirect bandgaps of 1.34 eV and 1.36 eV, respectively, featuring valence electrons that are strongly localized statically. In contrast, the 1T phase is confirmed to be metallic (0 eV bandgap) due to massive electron delocalization. These characteristics align with their optical responses, where the 2H and 3R phases are transparent at low energies and effectively absorb the visible to ultraviolet light spectrum. Meanwhile, the 1T phase exhibits ideal metallic optical behavior, marked by an extreme spike in the imaginary dielectric function at photon energies near zero and very high reflectance in the infrared region. Through a comparison of these three phases, this study is expected to provide a solid theoretical foundation regarding structure-property interactions in in MoS2 while offering predictive guidance for advanced material engineering.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Density Functional Theory, Elektronik, Molybdenum Disulfide, Optik, Polimorfisme, Quantum ESPRESSO, Density Functional Theory, Electronic, Optic, Molybdenum Disulfide, Polymorphism, Quantum ESPRESSO.
Subjects:	Q Science > QC Physics Q Science > QC Physics > QC100 Crystals. Q Science > QC Physics > QC111 Density and specific gravity
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Physics > 45201-(S1) Undergraduate Thesis
Depositing User:	Fadilah Siti Mukaromah
Date Deposited:	24 Jul 2026 07:30
Last Modified:	24 Jul 2026 07:30
URI:	http://repository.its.ac.id/id/eprint/137170

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