Role of Thickness towards the Optical and Electrical Properties of Photoactive Layer MEH-PPV: TiO₂ Nanocomposite Thin Films

Abstract:

In recent years, the research on organic solar cells systems based on nanocomposite containing conjugated polymers has lead to great attention with the aim or replacing conventional inorganic solar cells. This nanocomposite can be processed at lower cost, low weight and ease of synthesis with greater versatility than todays solar cell. In this study, we investigated the dependence of physical, optical and electrical properties on the thickness of MEH-PPV: TiO₂ nanocomposite thin films for organic solar cell application. It was found the optical properties of photo-active layer MEH-PPV: TiO₂ nanocomposite thin films improved with increasing its thickness however the electrical properties decreased. The absorption coefficients of photoactive layer are high in the visible region (400-600 nm) with optimum absorption region at 500 nm. The shift of absorption edge toward longer wavelength with increased of nanocomposite photoactive layer thickness due to narrowing band gap caused by the effects of electron-electron and electron-impurity scattering. In addition the study of illuminated current-voltage (I-V) characteristics revealed the increment of recombination process with increased of photoactive layer thicknesses. It was found such increased in resistivity from 136x10³ to 1600x10³ Ω.cm is closely related to the electric field and exciton dissociation which is decreased with increased photoactive thickness.

• Periodical: Advanced Materials Research (Volume 832)
• Pages: 404-409
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.832.404
• Online since: November 2013
• Authors: Fazlinashatul Suhaidah Zahid, Puteri Sarah Mohamad Saad, Mohamad Rusop Mahmood
• Keywords: Absorption Coefficient, MEH-PPV, Photoactive Thickness, Resistivity, TiO₂

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