Improving the Efficiency of Dye-Sensitized Solar Cells via the Impact of Triphenylamine-Based Inventive Organic Additives on Biodegradable Cellulose Polymer Gel Electrolytes

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 TiO2 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,N-diphenylaniline (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: TiO2/N-3 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).