Comparison of charge transport and opto-electronic properties of pyrene and anthracene derivatives for OLED applications

Abstract

In this paper, three organic semiconductors such as 9-[(5-nitropyridin-2-aminoethyl)iminiomethyl]-anthracene (a), N′-((pyren-4-yl)methylene)isonicotinohydrazide (b), and novel organic semiconductor N-(2-((pyren-4-yl)methyleneamino)ethyl)-5-nitropyridin-2-amine (c) were prepared. Their structures were assessed using NMR and elemental analysis techniques. While compound (a) and compound (c) have the same wing unit ([(5-nitropyridin-2-aminoethyl) iminiomethyl]), compounds (b) and (c) have the same core unit (5-nitropyridin-2-amine). Based on TD-DFT and Marcus theories, we have explored the effects of molecular structure on the opto-electronic properties for OLED applications. Our results show that wing units of molecules impact more on the opto-electronics properties than on core units. The compounds (a) and (c) with the same wing unit have exhibited quite similar behaviors in terms of both structural and opto-electronic parameters. However, a similar situation has not been observed for compounds (b) and (c) with the same core unit. In conclusion, our results indicate that compounds (a) and (c) exhibit obvious advantages for OLEDs in terms of calculated opto-electronic and charge transport properties such as better absorption and emission parameters, lower energy gaps and reorganisation energies and higher charge mobility.