Efficient Bilayer Light-Emitting Diode Based on Distyrylarylene-Containing Polymers: Numerical and DFT Simulation

In this article, we report a combined experimental and theoretical study on the optoelectronic properties of two semi-conducting polymers containing different pi-conjugated sequences [distyrylphenylene (P-DSP) and distyrylbithiophene (P-DSBT)]. Theoretical calculations were conducted, based on time-dependent density functional theory and Marcus theories, to predict the optical, electronic, and charge transport properties of the studied polymers. These results were compared with the experimental ones measured using UV-vis and photoluminescence (PL) spectroscopies. The P-DSBT polymer shows good absorption with a maximum absorption wavelength of 426 nm and a green emission with a maximum wavelength of 508 nm. Besides, the calculated characteristics showed that P-DSBT has better electron and hole mobilities of 7.9 x 10(-6) cm(-2) V-1 s(-1) and 3.4 x 10(-6) cm(-2) V-1 s(-1), respectively. A numerical simulation of ITO/polymer/Al device using the Silvaco Tecad simulator was reported and fitted to the experimental data and the results reveal an excellent overlap with the experimental ones. Moreover, the simulation of ITO/polymer/Alq(3)/Al bilayer organic light-emitting diode (OLED) has been performed and electrical behavior enhancement was evidenced compared with the monolayer device with a maximum current decrease from 9 to 49 mA, using P-DSBT polymer.

Automated summary

This article presents a study on the optoelectronic properties of two semi-conducting polymers through a combination of experimental and theoretical approaches. Theoretical calculations based on density functional theory and Marcus theories predicted the optical, electronic, and charge transport properties of the polymers, which were compared with experimental results. The P-DSBT polymer exhibited better electron and hole mobilities, and numerical simulations confirmed the enhancement in electrical behavior in a bilayer OLED device compared to a monolayer device.