Publication Details
Issue: Vol 6, No 3 (2025)
Pages: 1047-1058
ISSN: 2660-4159

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.

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