Benzothiazole functionalized diketopyrrolopyrrole photosensitizer for CdS nanowire based DSSC applications

Abstract

Although dye sensitized solar cell (DSSC) make promising progress for solar energy conversion to electrical energy, there are still great need for further research work to develop an efficient sensitizer with a simple synthetic protocol. In this study, two chromophores (E)-2-(benzo[d]thiazol-2-yl)-3-(5-(2,5-bis(2-ethylhexyl)-3,6-dioxo-4-(thiophen-2-yl)-2,3,5,6-tetrahydropyrrolo[3,4-c]pyrrol-1-yl)thiophen-2-yl)acrylonitrile (DPP-BTH1) and 3-(5-(2,2-bis(benzo[d]thiazol-2-yl)vinyl)thiophen-2-yl)-2,5-bis(2-ethylhexyl)-6-(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP-BTH2) are developed with broad range of absorption. The benzothiazole subunit 2-(benzo[d]thiazol-2-yl)acetonitrile (BTH1) and bis(benzo[d]thiazol-2-yl)methane (BTH2) auxiliary subunits were incorporated at the 5-(2,5-bis(2-ethylhexyl)-3,6-dioxo-4-(thiophen-2-yl)-2,3,5,6-tetrahydropyrrolo[3,4-c]pyrrol-1-yl) thiophene-2-carbaldehyde (DPP) core. DSSC devices with DPP-BTH1/CdS and DPP-BTH2/CdS nanowire photoelectrode under AM 1.5 G sun illumination exhibited power conversion efficiency of about 0.30 percent and 0.45 percent, respectively. The PCE is three and four-fold higher than that of bare CdS nanowire-based DSSC devices. These simple chromophores provide a promising perspective for next-generation photovoltaic devices to harvest sunlight efficiently.