Investigation of Structural and Optoelectronic Properties of Organic Semiconductor Film Based on 8-Hydroxyquinoline Zinc

In this work, we investigated an organic semiconductor based on zinc 8-hydroxyquinoline (ZnQ(2)) and tetracyanoquinodimethane (TCNQ), which can be used as a photoactive layer in organic devices. The semiconductor was optimized by applying density-functional theory (DFT) methods, and four hydrogen bridges were formed between ZnQ(2) and TCNQ. Later, thin films of ZnQ(2)-TCNQ were successfully deposited. The films were structurally and morphologically characterized, and the optical characteristics of the photoactive layer were investigated using ultraviolet-visible spectroscopy and time-dependent density-functional theory (TDDFT) calculations. The comparison and analysis of the experimental and theoretical absorption spectra indicate that the optical bandgap of the photoactive layer is 2.4 eV. Additionally, a flexible photo device was manufactured with the active layer ZnQ(2)-TCNQ, and its electrical behavior was evaluated under dark and light conditions. The results show a significant change in the behavior of the device when radiation is eliminated; the layer is light sensitive. The electrical resistance in the flexible photo device is associated with the optical behavior of the materials that constitute the active layer.

Automated summary

This study optimized an organic semiconductor through density-functional theory methods, successfully deposited and characterized thin films of ZnQ(2)-TCNQ, investigated their optical properties, and determined the optical bandgap. A flexible photo device was manufactured with the active layer, showing significant changes in electrical behavior under light conditions.