Bulky N-substituents of 4-(hexyloxy) phenyl-substituted and 4-(hexylthio)phenyl-substituted triphenylamine (TPA) were successfully introduced into double-anchored phenothiazine (PTZ) dyes (TY1-TY3) as capping moieties for metal-free organic sensitizers in dye-sensitized solar cells (DSSCs). Among TY dyes, the N-substituent of 4-(hexyloxy)phenyl-substituted TPA provided the best steric matching to its double-anchored PTZ dye having a small π-bridge of thiophene (TY1) and thereby facilitated the most compact dye packing as well as formed the most integrated shelter layer on the TiO2 surface. Effective dark current suppression supported by TY1 resulted in a good DSSC performance of 10.47% at 1 sun and 21.2% at 1 klux (Philips T5 lamp) with the presence of chenodeoxycholic acid (CDCA) as the co-adsorbent; this cell efficacy was higher than that of the reference N719-based (9.10% at 1 sun) and HL5-based DSSCs (8.34% at 1 sun).
- dye-sensitized solar cells
- metal-free organic sensitizers
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Energy Engineering and Power Technology
- Materials Chemistry
- Electrical and Electronic Engineering