Dye-sensitized solar cells based on biopolymer gel electrolyte systems deal with the perspective of good power conversion efficiency with low-cost fabrication. In this work, we synthesized an electron-rich triphenylamine core as an organic additive for hydroxyethyl cellulose (HEC) polymer gel electrolytes with a redox couple (I − /I 3 − ), which is efficient for DSSCs. The presence of a more conjugated system and heteroatoms in additives paved the way for the whole mobility transport and quasi-Fermi level shift, which reduces the recombination reaction between the TiO 2 surface and I 3 − ion, enhancing the organic photovoltaic properties. The electrochemical and photovoltaic properties of HEC gel electrolytes without additives (bare HEC) and with an additive ( 4-(di(1H-pyrrol-2-yl)methyl)-N,Ndiphenylaniline (DPMDA), (1H-phenanthro[9,10-d]imidazol-2-yl)-N,N-diphenylaniline (PIDA), 4-(di(1H-pyrrol-2-yl)methyl)-N-(4-(di(1H-pyrrol-2-yl)methyl)phenyl)-N-phenylaniline (DPMPPA), N-(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)-4-(1H-phenanthro[9,10-d]imidazol-2-yl)-N-phenylaniline (DPIPA), tris(4-(di-(1H-pyrrol-2-yl)methyl)phenyl)amine (TDPMPA), and tris(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)amine (TPIPA)) were studied, respectively; one of the organic additive tris(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)amine [TPIPA]-based polymer gel electrolytes (A6: TiO 2 /N3 dye/HEC/I − /I 3− /TPIPA/Pt) showed good electrochemical properties, longer electron lifetime, and hence an improved photoconversion efficiency of 5.72% with better stability under light illumination of 100 mW/cm 2 .