Organic materials based with D– π –A structure based on thiophene and anthracene for application in dye-sensitized solar cells

Abstract

In search of new high-performance materials to be used in organic solar cells by changing the bridge of molecules already synthesized, we used the functional density theory (DFT) and Time-dependent density-functional theory (TD/DFT) with several methods such as B3LYP, PBEPBE, B3PW91, mPW1PW91 and the basic set 6-31G (d, p), the electronic structures and optoelectronic properties of four organic dyes based on 2-(6-substituted-anthracen-2-yl)-thiophene as the π conjugated bridge, different amines as electron donors, and cyanoacrylic acid group as an electron acceptor have been calculated and discussed theoretically in the aim to obtain the most suitable method. The calculated electronic levels HOMO, LUMO, and Egap of the studied compounds show that the B3LYP method with the 6-31G base set (d, p) offers better performances such as lower energy gap. Then, we studied the influence of the change of bridge (anthracene) by thiophene and benzene on the electronic, optical and photovoltaic properties of these organic dyes.TD-B3LYP functional was used to describe optoelectronic properties such as the UV–visible spectrum for the various compounds studied. Furthermore, the free energy of electron injection (ΔG inject), LHE and O.S were calculated and analyzed. In conclusion, the calculated results reveal that the new compounds studied can be used as good candidates for dye-sensitized solar cells (DSSC) due to its best electronic and optical properties and good photovoltaic parameters except for compound M3..