Sains Malaysiana
40(1)(2011): 17–20
Tuning
the Optical Band Gap of DH6T by Alq3 Dopant
(Penalaan Jurang Tenaga Optik DH6T dengan Menggunakan Bahan
Pendop Alq3)
Fahmi Fariq Muhammad*
& Khaulah Sulaiman
Department of Physics, Faculty of Science
University of Malaya, 50603 Kuala Lumpur, Malaysia
Diserahkan: 7 Disember 2009 / Diterima: 13 Julai 2010
ABSTRACT
Dihexyl-sexithiophene
(DH6T) was doped with tris (8-hydroxyquinolinate) aluminum (Alq3) to prepare
blends of DH6T/Alq3 by dissolving the mixture in the chloroform/hexane
co-solvent. Solid films with different thickness deposited on quartz substrates
were obtained from the blends via casting process. Optical absorption
spectroscopy has been performed to measure the optical band gap of pure and
doped DH6T as well as variations in the band gap with dopant concentration
(weight %). This variation in optical band gap with dopant concentration was
determined quantitatively with fitted and extrapolated techniques and observed
qualitatively from the red shift appeared along the optical absorption spectra.
The results showed that within a specific dopant content, the optical energy
gap, Eg of DH6T decreases from 2.69 eV to 1.8 eV with
increasing dopant concentration to 23.1%.
Keywords: Band gap tuning;
dihexyl-sexithiophene; doping; optical properties
ABSTRAK
Diheksil-seksitiofena
(DH6T) telah didopkan dengan tris (8-hidroksiquinolinat) aluminium (Alq3) bagi
menyediakan adunan DH6T/Alq3 dengan melarutkan campuran-bahan dalam
pelarut-bersama klorofom/heksana. Filem nipis yang berbeza ketebalan diperoleh
melalui proses tuangan daripada campuran-bahan. Spektroskopi serapan optik
dijalankan untuk mengukur jurang tenaga optik bagi DH6T yang tulen dan DH6T
yang didopkan serta mengukur perubahan jurang tenaga dengan perubahan
ketumpatan bahan pendop (% berat). Perubahan dalam jurang tenaga optik dengan
ketumpatan pendop ini ditentukan secara kualitatif melalui teknik pemadanan dan
ekstrapolasi serta pemerhatian secara kualitatif daripada anjakan merah bagi spetrum
serapan optik. Keputusan menunjukkan bahawa jurang tenaga optik Eg DH6T
pada kandungan bahan pendop tertentu telah berkurang daripada 2.69 eV kepada
1.8 eV bila ketumpatan meningkat kepada 23.1%.
Kata kunci:
Diheksil-seksitiofena; penalaan jurang tenaga; pendopan, sifat optik
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*Pengarang
untuk surat-menyurat; email: fahmi982@gmail.com
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