Synthesis, characterizations, and comparative study of electro-optical properties of indole-based squaraine sensitizers as efficiency to enhancing dye-sensitized solar cells

Squaraine dyes (SQ) have acquired sufficiently great attention as dye-sensitized solar cell (DSSCs) materials. In the present study, we have synthesized and characterized of two novel symmetrical sensitizers dyes for dye-sensitized solar cells which contain electron withdrawing (−COOH) group with long alkyl ester chain (SQ1) and another without encoring group (SQ2). We have investigated the structural, electronic, photo-electrochemical, and charge transport properties of two SQ1& SQ2 indole-based squaraine dyes. The ground state geometry has been computed by applying density functional theory (DFT). The excitation energy and the oscillator strength were calculated by using time-dependent (DFT-TD) at DFT/B3LYP/6-31G** level of theory. We have focused and study on the frontier molecular orbitals (HOMO and LUMO), electron injection (ΔG inject ), light harvesting efficiency (LHE), open-circuit voltage (Voc), relative electron injection (ΔGr inject ), and short-circuit current density (Jsc)