We have evaluated the effect of π-electron system in donor-π-acceptor (D-π-A) based organic dyes and observed the performances in dye sensitized solar cell (DSSC). Various π-conjugation structures with different molecular arrangements with and without possessed π-conjugation system were successfully evaluated with custom molecular organic dyes D-1, U01, AK-01, TA-St-CA, Ba-03 and YF02. The introduction of conjugated π-system in the D-π-A system elevated wide range of absorption spectra from 300 nm to 850 nm wavelength region. The DSSC based on dyes D-1, U01, AK-01, TA-St-CA, Ba-03 and YF02 showed onset absorption of 525 nm, 600 nm, 650 nm, 550 nm, 810 nm and 550 nm correspondingly on the TiO2 film. A dip at the IPCE spectra in the 350 nm-470 nm wavelength region for dye D-1and U01 were attributed to the competitive absorption of solar spectrum of I3- solution. The AK-01 and BA-03 dyes showed IPCE of 70% at the 360 nm–620 nm region and subsequently reaches up to a maximum of 84% at 450 nm. The U01 dye depicts IPCE of 70% at 400 nm–560 nm and peaks of 86% at 500 nm within the visible region. The sensitized YF02 dye reaches up to 75% at 350 nm-550 nm. The greater IPCE value of AK-01, TA-St-CA, YF02 and BA-03 in the UV zone suggested that these organic dyes successfully surpassed the dip of IPCE spectrum in that region. The photovoltaic performances of these sensitizers were verified by incident-photon-to-current conversion efficiency (IPCE), open-circuit photovoltage (Voc), short-circuit photocurrent density (Jsc) and total Power conversion Efficiency (Æž). Dyes D-1 and U01 were without any π-linker showed Æž of 3.34% and 6.01% exhibiting Jsc of 6.42 mA cm-2 and 10.70 mA cm-2 respectively. Dyes with a π-conjugated oligo-phenylenevinylene unit linker showed Æž of 6.2% (AK-01), 5.41% (TA-St-CA) and 5.29 (YF02), dye with a fused dithienothiophene π-conjugated linker showed Æž of 6.38% (Ba-03) respectively. The corresponding Jsc of dyes AK-01, TA-St-CA, Ba-03 and YF02 were 15.40 mA cm-2, 10.10 mA cm-2, 16.17 mA cm-2 and 9.19 mA cm-2 followed by Voc of 0.640 V, 0.718 V, 0.595 V and 0.799 V respectively. The comparative analysis of IPCE reveals the effect of π-electron of these dyes to increase their corresponding light harvesting ability, reduced dye aggregation and low carrier recombination in DSSCs operation.