Sains Malaysiana 39(4)(2010): 627–631

Effects of Annealing Temperature on the Optical Properties and Device Performance of Ag / n-Si / CuPc / Ag Solar Cell Prepared via Spin Coating Method

(Kesan Suhu Sepuh Lindap ke atas Sifat Optik dan Prestasi Peranti Sel Suria Ag / n-Si / CuPc / Ag yang disediakan Melalui Kaedah Salutan Berputar)

HanashriahHassan*, Noor Baa’yahIbrahim& Zahari Ibarahim

School of Applied Phyics, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

Diserahkan: 14 Ogos 2009 / Diterima: 5 November 2009

ABSTRACT

Copper phthalocyanine (CuPc) thin films have been prepared using a simple spin coating method. The films were annealed at 5 different temperatures (323, 373, 473, 523 and 573 K) for one hour in air. Optical properties study using the UV-Vis spectrophotometer showed that in the range of wavelength of 300-800 nm, all of the films have identical absorption coefficient patterns and there was no systematic changes with respect to annealing temperature. The film annealed at 373 K showed the highest absorbance while the lowest absorbance was shown by the film annealed at 323 K. The results showed that the optical band gaps depended on the temperature. The film annealed at 373 K has the lowest optical energy gap. Using the five annealed films, solar cell with the configuration of Ag / n-Si / CuPc / Ag were fabricated. Under the 50 W/cm2 light illumination, the current voltage measurements at room temperature were carried out on the device. The device which consists of film annealed at 373 K exhibited the best photovoltaic characteristics. The different annealing temperature also affect the photovoltaic behavior of the devices in a non-systematic way.

Keywords: Annealing; current-voltage; optical band gap; solar cell

ABSTRAK

Filem nipis kuprum ftalosianina (CuPc) telah disediakan melalui kaedah ringkas salutan berputar. Filem tersebut disepuh lindap pada 5 suhu yang berbeza (323, 373, 473, 523 dan 573 K) selama satu jam dalam udara. Sifat optik yang dikaji menggunakan UV-Vis spektrofotometer menunjukkan pada julat panjang gelombang 300-800 nm, semua filem mempunyai corak pekali penyerapan yang sama dan tiada perubahan sistematik terhadap suhu sepuh lindap. Filem yang disepuh lindap pada 373 K menunjukkan penyerapan tertinggi manakala penyerapan terendah ditunjukkan oleh filem yang disepuh lindap pada 323 K. Keputusan menunjukkan jurang tenaga optik adalah bergantung kepada suhu. Filem yang disepuh lindap pada suhu 373 K mempunyai jurang tenaga optik paling rendah. Menggunakan kelima-lima filem yang disepuh lindap itu, sel suria dengan konfigurasi Ag / n-Si / CuPc / Ag telah difabrikasi. Di bawah pancaran 50 W/cm2, pengukuran arus-voltan pada suhu bilik telah dilakukan ke atas peranti. Peranti yang mengandungi filem yang disepuh lindap pada 373 K mempamerkan ciri fotovoltaik terbaik. Suhu sepuh lindap yang berbeza juga memberi kesan kepada sifat fotovoltaik peranti secara tidak sistematik.

Kata kunci: Arus-voltan; jurang tenaga optik; sepuh lindap; sel suria

RUJUKAN

Abraham, C.V. & Menon, C.S. 2005. Electrical conductivity studied of mixed phthalocyanine thin films. Central European Journal of Physics 3(1): 8-14.

Ambily, S. & Menon, C.S. 1999. The effect of growth parameters on the electrical, optical and structural properties of copper phthalocyanine thin films. Thin Solid Films 347: 284-288.

Bardeen, J., Blatt, F.J. & Hall, L.H. 1965. Indirect transitions from the valence to the conduction bands. Proceeding of Conference on Photoconductivity: 149-154.

Chen, C.H. & Shih, I. 2006. Hybrid organic on inorganic semiconductor heterojunction. J Mater Sci: Mater Electron 17: 1047-1053.

El-Nahass, M.M., Farid, A.M., Farag, A.A.M. & Ali, H.A.M. 2006. Carrier transport mechanisms and photovoltaic characteristics of p-H2Pc / n-Si heterojunction. Vacuum 81: 8-12.

El-M.M. & Yaghmour, S. 2008. Effect of annealing temperature on the optical properties of thermally evaporated tin phthalocyanine thin films. Applied Surface Science 255: 1631-1636.

Farag, A.A.M. 2007. Optical absorption studies of copper phthalocyanine thin films. Optics & laser Technology 39: 782-732.

Hoshi, H., Dann, A. & Maruyama, Y. 1990. The structure and properties of phthalocyanine films grown by the molecular beam epitaxy technique. II. Ultraviolet visible spectroscopic study. Journal of Applied Physics 67: 1845-1849.

Inigo, A.R., Xavier, F.P. & Goldsmith, G.J. 1997. Copper Phthalocyanine as an efficient dopant in development of solar cells. Materials Research Bulletin 32(5): 539.

Karimov, Kh. S., Ahmed, M.M., Moiz, S.A. & Fedorov, M.I. 2005. Temperature dependant properties of organic-on-inorganic Ag /p-CuPc / n-GaAs / Ag Photoelectric Cell. Solar Energy Materials and Solar Cell 87: 61-75.

Levitsky, A. 2004. Hybrid Solar Cells based on porous Si and copper phthalocyanine derivatives. Applied Physics Letter 85(25): 6245-6247.

Prabakaran, R., Fortunato, E., Martins, R. & Ferreira, I. 2008. Fabrication and characterization of Hybrid Solar Cells based on copper phthalocyanine/porous silicon. Journal of Non-Crystalline Solids 354: 2892-2896.

Shaji, V., Mercy, I., Mathew, E.J. & Menon, C.S. 2002. Determination of energy gap of thin films of cadmium sulphide, copper phthalocyanine and hybrid cadmium sulphide/copper phthalocyanine from its optical studies. Materials Letters 56: 1078-1083.

Sharma, G.D., Raj Kumar, Shailendra Kumar Sharma & Roy, M.S. 2006. Solar Energy Materials and Solar Cell 90: 933-943.

Smertenko, P.S., Kostylev, V.P., Kislyuk. V.V., Syngaevsky, A.F., Zynio, S.A. & Dimitriev, O.P. 2008. Photovoltaic cells based on Cadmium sulphide-phthalocyanine heterojunction. Solar Energy Materials and Solar Cells 92: 976-979.

Yakuphanoglu, F., Kandaz, M. & Senkal, B.F. 2008. Current-Voltage and Capacitance Voltage Characteristics of Al / p-type silicon/organic semiconductor based on phthalocyanine rectifier contact. Thin Solid Films 516: 8793-8796.

Yuki, Y., Makoto, M., Senku, T., Ichiro, H., Yasuhisa, F. & Katsumi, 2006. Photovoltaic Properties and inner electric field of ZnO/Zn-phthalocyanine hybrid solar cells. Synthetic Metals 156: 1213-1217.

*Pengarang untuk surat-menyurat; email: baayah@ukm.my