Synthesis Of Novel Pure Organic Dyes And Application Research In The Dye-Sensitized Solar Cells

As the key component of the dye-sensitized solar cells (DSSCs), designing highly efficient and stable photo-sensitizers is important to improve the photon-to-electron conversion efficiency and beneficial for the industrial application of the DSSCs. Several series of the dyes have been synthesized. The physical, electrochemical properties and photovoltaic performance of the solar cells have been investigated systematically.A series of D-π-A structured iso-quinolinium organic dyes without vinyl group have been synthesized. When applied in DSSCs, dye JH304-based solar cells yield the best photon-to-electron conversion efficiency of7.3%(Jsc=14.40mA·cm-2,Voc=684mV, FF=74.4%). Iso-quinolinium and carboxyl group was separated by-CH2-units. When the number of the-CH2-units increased, the efficiency of the DSSCs decreased from6.8%to4.2%. However, different from iso-quinolinium dyes, the efficiency of rhodanine organic dyes can be improved from4.1%to4.5%with the increase of the number of-CH2-units.Hydroxyl group was employed in D-π-A structured dyes as anchoring group. Based on that, a series of pyridinium organic dyes with different electron donors have been synthesized and the effect on the photovoltaic performance was investigated systematically. Finally, an efficiency of2.6%was achieved by JH401-based device. Meanwhile, an80%IPCE value was obtained at440nm, which is the highest IPCE response in hydroxyl adsorbent organic dyes up to now.A series of phenanthrenequinone derivatives based organic dyes with different electron donor and π-conjugated bridge were synthesized. When applied in DSSCs, JH203-based device exhibited the best photon-to-electron efficiency of6.0%(Jsc=11.13mA·cm-2, Voc=720mV, FF=74.9%). Aging test indicates that phenanthrenequinone derivatives organic dyes exhibit a good stability.Phenothiazine based D-π-A and D-A-π-A structured dyes indicate that D-A-π-A structured dyes exhibit longer and more broaden absorption response but a lower molar extinction coefficient. Under the same condition, D-π-A structured organic dyes produce a higher efficiency of7.5%(JSc=16.36mA·cm-2, Voc=706mV, FF=64.5%), while D-A-π-A structured dyes yield an efficiency of6.4%(Jsc=14.71mA·cm-2, Voc=645mV, FF=67.3%).