Preparation and investigation of the optoelectronic properties of alkoxy-bridged triphenylene and perylene monoimide diester dyad films

Abstract

Herein, alkoxy-bridged triphenylene and perylene monoimide diester dyads (TP-C_n-PMI, n = 4, 6, and 10) were designed and synthesized, and their films were successfully prepared on the surfaces of platinum and indium tin oxide (ITO) glass electrodes by electrochemical deposition. The electrochemical deposition was carried out for different times (30, 60, 180, 300, and 600 s) in tetrahydrofuran (THF) using tetrabutylammonium hexafluorophosphate (TBAPF6) as the supporting electrolyte. The morphology, thickness, and optical properties of the films were characterized using photoluminescence (PL), scanning electron microscopy (SEM), polarized optical microscopy (POM), and atomic force microscopy (AFM). The morphology, thickness, and photocurrent density of the three dyad films were directly correlated with the prolongation of electrochemical deposition time. The results indicate that the films of the three dyads deposited for 60 s exhibited a comb-like texture with a more regular and orderly distribution, leading to higher photocurrent density. The triphenylene and perylene units of the dyads in the films predominantly align in a homeotropic (face-on) orientation. This study introduces an effective strategy for modulating the morphology, thickness, and photocurrent density of the films, thereby presenting a promising active layer material for organic solar cells.