A solid-state photoelectrochemical solar energy conversion device based on blend ofrnpoIY(3 -hexy lthi ophene) (P3HT) and 1- (3-methoxycarbony l)propyl- l-phenyl (6,6]C61rn(PCBM), and an amorphous poly(ethylene oxide) complexed with 1)-11- redox couplernhas been constructed and characterized. The photoelectroc hemical perfonnanc(rnparameters of the device were compared with pure P3HT and P3HT:C60 blend solidÂ·rnstate photoelectrochemical ce ll. The current density-vo ltage characteristics in the darlrnand under white light illumination and photocurrent spectra fo r front and backsidtrnilluminations have been studied. An open-circuit voltage of 140 mV and a shonrncircuit current density of 28.4 ~cm 2 at light intensity of 100 mW/cm2rn; IPCE% 0rn1.52% fo r fron t side illumination (lTOIPEDOT) and IPCE% of 0.17% for backsid,rnillumination (ITOIP3HT:PCBM) at a wavelength of 510 nm were obtained. Thrndependence of the short-circuit current density and an open-c ircuit vo ltage on the lighrnintensity and time have also been studied.rnA so lid-state photoelectrochemical solar energy conversion dev ice based on nc-TiCrnsensit ized with D i-Tetra buty lammon i u rncis-bi s( iso! h iocyanato )bis(2 ,2 ' -bi pyrid y.rn4,4 '-dicarboxylato)-rutheniumOI) (N-719) dye has been constructed anrncharacterized. The current-voltage characteristics in the dark and under whi te liglrnillumination and action spectra under monochromatic illuminations have been studie.rnThe fo llowing dev ice parameters were obtained: an open-c ircuit vo ltage of762.5 111 'rnand a short circuit current density of 33.2 IJA/cm2 at light inten sity 00 mW/cm2; thernIPCE% obtained was 1.7% at 330 nm. The dependence of the short-circuit current andrnan open-circuit vo ltage on the incident light inte nsity and illumination time have a lsornbeen studied.rnOSSCs were assembled using natural dye extracted from fruits of Ookma (Syzygillmrngllineense) as sensitizer. The photoelectrochem ical performance of the quasi-solidrnstate OSSCs based on the ethanol extract dye showed Voc of 0.506 V and lsc of2.03rnmAcm -2; and a power conversion effi c iency of 0.51 %. UV-vis spectroscopy studi e~rnof light absorption of the nalural dye were done. Furtherm ore, the ethanol extracirnobtained from Syzygillm guineense was further purified stepwise through solventsolventrnextraction. The photoe lectrochemical performance for the extracts withrndifferent solvents indicated that the ind ividual components have synergisti c effect irrnthe performance of the OSSC.rnQuasi-solid state dye-sensit ized solar ce lls (OSSCs) were assembled by using the learnextracts of Amaranrhlls cal/dalus and Iresifle herbs/ii, and flower extract of Ipomoe(rnindica and HibisclIs sabdarifla as natural sensitizers of Ti02 fi lms. 0. 1 M HCI learnextracts of Amaranlhus calldatus and Iresifle herbsl;; mainly con tains the ye llovrnorange ind icaxanthin and the red purp le betacyanin whereas their respective ethanernextract is mainly chlorophyll. In ethanol and 0.1 M He l extract of Ipomoea indica anrnHibisclls sabdarifla anthocyani ns are the main components. The best overall so larnenergy conversion effic iency of 1% was obta ined, under 100 mW/cm2 irrad iatiOirnwith ethanol extract of Amaral/thus caudalwi, that showed a current density (l sern3.44 mNcm2rn), open circuit voltage (Voc "" 0.57 V), and a high IPCE va lue (77% atrn"" 4 10 nm). Also the ethanol extract of Ipomoea indica fl ower showed interestinrnperfollTlances, with a Jsc of3. 11 mAlcm2rn, Yoc of 0.55 Y, the corresponding solar tornelectrical power conversion of efficiency of 0.94% and IPeE va lue (75% at A"" 420rnnm). The ethanol extract of Hibiscus sabdariffa flower showed Jsc of 3.21 mNcm2rn,rnYoc of 0.49 Y, the corresponding solar to electrical power conversion of efficiency ofrn1% and IPeE va lue (50 .2% at A = 600 nm).