Theoretical study on energy levels and photophysical properties of p-n block oligomers

Recently, a novel series of oligomers consisting of thiophene as p-type unit and oxadiazole as n-type unit were successfully synthesized. In this article, we present a first-principles study of the electronic, and optical properties on p-n diblock and triblock oligomers systematically. Theoretical studies showed changing the number of thiophene and oxadiazole unit could effectively modulate the electronic properties of p-n diblock and triblock oligomers. The electronic and photophysical properties of theoretical calculation results were in consistent with observed experimental results. These results provide useful guidelines to control the band gap principle of p-n hereostructure oligomers systems, and fundamental insights into understanding the electronic and photophysical properties in p-n hereostructure oligomers systems.