An Experimental Study of Some Optical Properties of The Organic Semiconductor Molecule (Alq3)

Ahmed Saad  Abd; Abdul Hakeem Shakor  Mohamed

doi:10.17605/cajmns.v6i3.2805

Ahmed Saad Abd Department of Physics-College of Education for Pure Sciences-University of Kirkuk-Kirkuk-Iraq
Abdul Hakeem Shakor Mohamed Department of Physics-College of Education for Pure Sciences-University of Kirkuk-Kirkuk-Iraq

DOI: https://doi.org/10.17605/cajmns.v6i3.2805

Keywords: Absorption Coefficient, Dielectric Constant, Optical Extinction Coefficient, Optical Conductivity, Organic Semiconductor, Refractive Index

Abstract

In this research, an experimental study was conducted to analyze the spectral effects of different concentrations of the organic semiconductor Tris(8-hydroxyquinoline)aluminum (Alq₃), using UV-Vis absorbance measurements in the spectral range of (200–1100) nm. Three samples were prepared with concentrations of (0.01, 0.02, 0.03) mM and a set of main optical properties were analyzed, including the absorption coefficient (α), refractive index (n), optical extinction coefficient (k), real (ε₁) and imaginary (ε₂) dielectric constants, in addition to optical conductivity (σₒ).The results showed that increasing the concentration of Alq₃ leads to a significant improvement in photon absorption and intensification of the optical response, attributed to enhanced molecular packing and increased density of optically active centers. Additionally, distinct electronic transition peaks of the π*→π and n*→π kinds were detected, indicating the possibility of improving the material's optical qualities for use in organic optical devices including organic solar cells and light-emitting diodes (OLEDs). This study emphasizes how crucial it is to regulate the material's concentration as a useful factor for precisely adjusting its electrical and spectral characteristics.

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