摘要： A series of new pyridomethene-BF 2 /phenothiazine hybrid metal-free organic sensitizers K1-K8 containing different π-spacers were synthesized and applied in dye-sensitized solar cells (DSSC). The introduction of the pyridomethene-BF 2 complex unit to the phenothiazine chromophore resulted in a high molar extinction coefficient in favor of light harvesting. Quantum chemical calculations were performed using the density functional theory (DFT) at the B3LYP/6-31G(d,p) level to investigate the structural properties and electron density distributions of these dyes. The effect of dyes K1-K8 on the performance of DSSC was investigated systematically with comparisons to the plain phenothiazine dyes R1 and R2 . Upon co-adsorption with deoxycholic acid, the dye K3 , with a thiophene unit between the phenothiazine and pyridomethene-BF 2 units, exhibited the best photovoltaic performance. The short-circuit current density ( J sc ) was 15.43 mA cm −2 with an open-circuit voltage ( V oc ) of 0.69 V and a fill factor (FF) of 0.62, which correspond to a power-conversion efficiency ( η ) of 6.58% under AM 1.5G irradiation (100 mW cm −2 ). The n -hexyl chain attached to the thiophene in K4-K5 improved the V oc value. The presence of the phenyl pyridomethene-BF 2 moiety at the N(10) atom of phenothiazine in K6-K8 reduced π-π aggregation. These results reveal the advantage of incorporating a pyridomethene-BF 2 group in the dyes for high-performance DSSC cells. Organic dyes containing both phenothiazine and pyridomethene-BF 2 moieties displayed the highest power-conversion efficiency 6.58% under AM 1.5G irradiation condition. 出版日期： 2015-08-04 資源來源： Royal Society of Chemistry 識別號： ISSN: 2050-7488 識別號： EISSN: 2050-7496 識別號： DOI: 10.1039/c5ta03807c
