Synthesis And Characteristics Of Triphenylamine With Anthracene Unit Arylene-ethynylenes

Dye-sensitized solar cells?DSSCs?is a novel of photovoltaic devices which can convert solar energy into electrical energy.Its preparation process is relatively simple and the cost is relatively low.Photosensitizer is the key compoent for the DSSCs,which determines the performance of the battery.The high efficiency DSSCs reported recently always sensitized by dyes with triple bond.In order to study the influence of the introduction of ethynyl on the performance of dyes,we have synthesized five organic dyes containing a D-?-A structure.The molecular structures are based on a push-pull framework with a triphenylamine as the donor connected to a carboxylic acid group or cyanoacrylic acid group as the acceptor.SC101 applied a anthracene-monoyne unit as the ?-conjugation,while SC102 and SC103 were replaced with a anthracene-monoyne unit.SC104 and SC105 were synthesized based on SC102 and SC103,theywere designed by introducing a triple bond between the triphenylamine and anthracene.The structures of the dyes have been characerized by proton nuclear magnetic resonance(¹H NMR and ¹³ CNMR)technology.At the same time,Their optical,electrochemical properties and photovoltaic parameters of DSSCs sensitized by these dyes were systematically investigated.The results showed that the major absorption peaks of SC102 and SC103 with diyne unit have a slight red shift compared to SC101 with monoyne unit,and the range and intensity of absorption spectra are broader and stronger than SC101.Compared with SC102 and SC103,similarly,SC104 and SC105 exhibited the same performances.These results indicated that the introduction of triple bond could broaden the dye's absorption spectra due to the enhancement of the ?-spacer.We have studied the photovoltaic properties of the dyes.The results revealed that SC105 has the best performances.It displayed a high power conversion efficiency of 4.14%,and increased 167% compared to SC101?1.55%?.The power conversion efficiency of cells based on SC102-103 is 3.12%,2.98% and 3.08%.SC105 has a remarkably higher electron lifetime in the TiO₂ conduction band and greater dye load on TiO₂ than the other dyes,these guaranteed a higher short-circuit photocurrent density and open circuit voltage.Thus,the cell based on SC105 has the best photovoltaic properties.These results indicated that the different introduction of triple bond could benifit the perfomance of DSSCs significantly.