Electrical and Molecular Engineering of π-Conjugated Polymers for Multilayer OLED Application

摘要

In this paper, a combined theoretical and experimental study into the properties of two $pi$ -conjugated polymers with different spacers were investigated. Theoretical calculations were performed using density functional theory (DFT), TDDFT and Marcus theories, to predict the optoelectronic and charge transport properties. As a result, polymer with thiophene spacer shows good optical properties and green emission with a maximum wavelength $lambda_{ext{emis}}=508 ext{nm}$. These results are in good agreement with the experimental data. Furthermore, the calculated results show that thiophene polymer has better electron and hole mobility equal to 7.32 $10^{-6} mathrm{cm}^{2}mathrm{V}^{-1}mathrm{s}^{-1}$ and $3.10 10^{-6} ext{cm}^{2} mathrm{V}^{-1}mathrm{s}^{-1}$, respectively. Using these properties, current-voltage characteristics of a multilayer organic light emitting diode based on the studied polymers are performed using a physically based device simulator Silvaco Atlas. Good electrical properties are obtained for thiophene polymer compared to phenylene with a turn-on voltage equal to 5.9 V.