A new photosensitizer having two rhodanine acetic acid groups at meso-positions of a zinc porphyrin [meso-Rhod-Zn-Rhod] has been synthesized and characterized by UV-Visible, ¹H NMR, MALDI-MS, fluorescence spectroscopies and cyclic voltammetry. The new photosensitizer was tested in dye-sensitized solar cells with three different liquid redox electrolytes and compared its efficiency (𝜂) with dyad. Both dyad and triad were also tested in DSSC using a polymer gel redox electrolyte and observed low efficiency because of small short circuiting current i.e. I_Sc though the IPCE is significantly high. The probable reason for the low efficiency small I_Sc has been attributed to the internal resistance of the cell.

We have designed and synthesized a new unsymmetrical zinc phthalocyanine based on `push-pull’ and extended 𝜋-conjugation concept, PCH008. The new sensitizer was fully characterized by CHN anlysis, UV-Vis., fluorescence spectroscopies and cyclic voltammetry. The new sensitizer which upon anchoring onto nanocrystalline TiO₂ film exhibit a short circuit current of 5.63 mA cm^-2, open circuit potential of 557.0 mV and a fill factor of 0.75 corresponding to an overall conversion efficiency of 2.35% under standard global air mass (AM) 1.5 solar conditions and compared its performance with literature reported phthalocyanine dyes.

Heteroleptic ruthenium(II) bipyridyl complex, cis-Ru(II)(4,4'-bis(4-tert-butylstyryl)-2,2'-bipyridyl) (4,4'-dicarboxy-2,2'-bipyridyl) (NCS₂) (H112) was synthesized and characterized by ¹H-NMR, MASS, Spectrofluorometer and UV-Vis spectroscopes. The photo-voltaic performance of the sensitizer was evaluated in Dye Sensitized Solar Cell (DSSC) under irradiation of AM 1.5 G solar light and the photovoltaic characteristics were compared with those of reference cells of HRS1 and N719 fabricated under comparable conditions. Compared to N719, H112 sensitizer showed enhanced molar extinction coefficient and relatively better monochromatic incident photon-to-current conversion efficiency (IPCE) across the spectral range of 400 to 800 nm with solar energy-to-electrical conversion efficiency (𝜂) of 2.43% [open circuit photovoltage (V_OC) = 0.631V, short-circuit photocurrent density (J_SC) = 8.96 mA/cm², fill factor (ff) = 0.430], while 𝜂 values of 2.51% (V_OC = 0.651V, J_SC = 9.41 mA/cm², ff = 0.410) and 2.74% (V_OC = 0.705 V, J_SC = 8.62 mA/cm², ff = 0.455) were obtained for HRS1 and N719 sensitized solar cells respectively. The introduction of 4,$4'$-bis(4-tert-butylstyryl) moieties on one of the bipyridine moieties of N719 complex shows higher light absorption abilities, IPCE and J_SC.

A new high molar extinction coefficient heteroleptic ruthenium(II) complex (m-BL-1) that contains a 4,4'4"-tricaboxy-2,2':6’,2”-terpyridine, 4,4’-bis-[3,5-di-tert-butyl-phenyl)-vinyl]-[2,2']bipyridyl and a thiocyanate ligand in its molecular structure has been synthesized and completely characterized by CHN, Mass, ¹H-NMR, UV-Vis, and fluorescence spectroscopies as well as cyclic voltammetry. The new sensitizer was tested in dye-sensitized solar cells using three different redox electrolytes and compared its performance to that of standard sensitizer black dye.