KAJIAN SIFAT OPTIK MENGGUNAKAN SPEKTROSKOPI ELIPSOMETRI TERHADAP LAPISAN BULK-HETEROJUNCTION REDUCED GRAPHENE OXIDE/PCBM YANG DISINTESIS MENGGUNAKAN METODE VACUUM DROP CONSOLIDATION

SAMUEL POLONTALO, Dr. Iman Santoso, S.Si., M.Sc

2020 | Skripsi | S1 FISIKA

Telah dilakukan kajian sifat optik lapisan tipis Bulk Heterojunction pada reduced Graphene Oxide(rGO) doping PCBM dengan berbagai volume. Graphene Oxide(GO) diperoleh dari sintesis secara kimia menggunakan metode Hummer's. Reduced Graphene Oxide (rGO) diperoleh dari proses reduksi GO dilakukan secara kimia menggunakan hydrazine hidrate. Telah dilakukan blending rGO dan PCBM([6,6]-phenyl-C61-butyric acid methyl ester) sehingga didapatkan Bulk-Heterojunction rGO/PCBM. Pengkajian sifat optik pada penelitian ini dilakukan dengan mengekstraksi data psi dan delta Bulk-Heterojunction rGO/PCBM yang diperoleh dari spektroskopi elipsometri. Kemudian data psi dan delta diekstraksi dengan persamaan Drude-Lorentz menggunakan perangkat lunak RefFit. Dari hasil ekstraksi didapatkan sifat optik indeks bias (n,k) dan konstanta dielektrik (epsilon1,epsilon2). Telah diperoleh nilai epsilon2 menurun pada rentang energi 1,3-4,5 eV seiring dengan pertambahan volume PCBM dan nilai k menurun pada rentang energi 1,3-5 eV seiring dengan pertambahan volume PCBM. Berdasarkan hasil sifat optik yang diperoleh tersebut dapat disimpulkan bahwa kemampuan rGO menyerap cahaya semakin rendah, karakter rGO semakin transparan dan adanya penurunan konduktifitas rGO.

Study of the optical properties of the thin layer Bulk Heterojunction at reduced Graphene oxide (rGO) with various concentrations has been carried out. Graphene Oxide(GO) is obtained from chemical synthesis using a modified Hummer method. Reduced Graphene Oxide (rGO) obtained from the GO reduction process is carried out chemically using hydrazine hydrate. Blending of rGO and PCBM([6,6]-phenyl-C61-butyric acid methyl ester) has been done so that we get the Bulk-Heterojunction rGO/PCBM. The study of optical properties in this study was carried out by extracting psi and Delta Bulk-Heterojunction rGO/PCBM data obtained from ellipsometry spectroscopy. Then the psi and Delta data were extracted using the Drude-Lorentz equation using RefFit software. From the extraction, the optical properties of refractive index and dielectric constant were obtained. It has been found that the value of varepsilon2 decreases in the energy range of 1.3-4.5 eV as the volume of PCBM increases and the value of k decreases in the energy range of 1.3-5 eV as the volume of PCBM increases. Based on the results of the optical properties obtained, it can be concluded that the ability of rGO to absorb light is lower, the character of rGO is more transparent and there is a decrease in the conductivity of rGO

Kata Kunci : Elipsometri, lapisan tipis, PCBM, reduced graphene oxide, sifat optik,