Pengaruh Konsentrasi P3HT:PCBM pada Reduced Graphene Oxide Terhadap External Quantum Efficiency (EQE) Sel Surya Organik Bulk Heterojunction

PUTU EKAYANI SRI T, Dr. Iman Santoso, S.Si., M.Sc.

2020 | Tesis | MAGISTER FISIKA

Sel surya organik (SSO) telah dibuat menggunakan material reduced graphene oxide (rGO), polimer poly-3-hexylthiophene (P3HT) dan phenyl-C61-butyric acid methylester (PCBM). Material rGO, P3HT dan PCBM masing-masing bertindak sebagai hole transport layer (HTL), donor dan akseptor lapisan aktif. Kajian diawali dengan sintesis rGO dengan metode Hummer dengan variasi temperatur reduksi 60, 70, 80, dan 90 oC. Hasil karakterisasi menggunakan spektroskopi Raman, spektroskopi UV-Vis, spektroskopi Fourier Transform Infrared (FTIR) dan High Resolution Transmission Electron Microscopy (HR-TEM) menunjukan bahwa rGO dengan temperatur reduksi 90 oC memiliki serapan paling tinggi. Selanjutnya dibuat blending rGO/P3HT:PCBM dengan variasi konsentrasi 2, 4, 6 dan 8 mg/mL dengan perbandingan P3HT:PCBM adalah 1:1. Kemudian dilakukan pengukuran EQE menggunakan spektrofotometer UV-Vis dan Keithley 2401A. Nilai energi gap dari spektrofotometer UV-Vis menggunakan metode Tauc adalah sekitar 2,279 eV. Pengukuran nilai EQE SSO pada panjang gelombang 550-650 nm dengan konsentrasi 2, 4 dan 6 mg/mL masing-masing sebesar 56,9; 60,9 dan 66 %. Nilai EQE tertinggi didapatkan pada konsentrasi 8 mg/mL yaitu sebesar 69,7 %. Hal ini menunjukkan bahwa konsentrasi blending rGO/P3HT:PCBM mempengaruhi nilai EQE pada SSO. Semakin tinggi konsentrasi, nilai EQE yang dihasilkan semakin meningkat pula.

Organic solar cells (OSC) have been made using reduced graphene oxide (rGO) materials, poly-3-hexylthiophene (P3HT) polymer and phenyl-C61-butyric acid methylester (PCBM). The rGO, P3HT and PCBM materials act as a hole transport layer (HTL), donor and acceptor of active layer, respectively. The study began with the synthesis of rGO using the Hummer method with a reduction temperature variation of 60, 70, 80, and 90 oC. The results of characterization using Raman spectroscopy, UV-Vis spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy and High Resolution Transmission Electron Microscopy (HR-TEM) show that rGO with a reduction temperature of 90 oC has the highest absorption. Furthermore, rGO/P3HT:PCBM blending was made with various concentrations of 2, 4, 6 and 8 mg/mL with a ratio of PCBM:P3HT of 1:1. Then, EQE measurements used a UV-Vis spectrophotometer and Keithley 2401A. The value of gap energy with UV-Vis spectrophotometer using the Tauc method is about 2.279 eV. Measurement of the SSO EQE value at a wavelength of 550-650 nm with a concentration of 2, 4 and 6 mg/mL is 56.9; 60.9 and 66 %, respectively. The highest EQE value was obtained at a concentration of 8 mg/mL is 69.7 %. This shows that the blending concentration of rGO/P3HT:PCBM affects the EQE value at SSO. The higher the concentration, the resulting increased EQE value as well.

Kata Kunci : SSO, rGO, P3HT:PCBM, Energi gap, EQE