Photophysical Behavior Of Triphenylamine Derivatives And Photoelectric Conversion Polymer Performance

First of all, 4-nitrotriphenylamine, 4,4′-dinitrotriphenylamine and 4,4′,4″-trinitrotriphenylamine were synthesized from condensation of diphenylamine, aniline,4-nitrophenylamine with 4-fluoronitrobenzene. Redution of nitrophenylamines to thecorresponding amino substituted triphenylamine using the C-Pd catalysts.Fluorescence spectrum and the absorption spectrum of each kind of triphenylaminederivative were tested under different solvent, temperature, concentration, and itsphotophysics performance was studied.A series of novel triphenylamine-containing aromatic diamine were synthesizedfrom the amination reaction between 4-aminotriphenylamine, 4, 4′-diaminotriphenylamine, 4, 4′, 4″-triaminotriphenylamine and perylene or naphthalenetetracarboxylic dianhydride. Their molecular structures were characterized byelementary analyses and FTIR measurements. The thermostability was investigatedby thermogravimetric analysis (TGA) and the differential Scanning Calorimetry(DSC). UV-Vis and the cyclic voltammetry (CV) was used to investigate the change ofthe energy level structure. Introduction of triphenylamine structure groups changed theentire dye system energy level, and the dye excited state energy level match to thetitanium dioxide conduction band energy level which favors electronic transmission.The change of aggregation way of aromatic diamine was studied by UV-Vis,photoluminescence spectroscopy (PL) and the molecular conformation simulation, andnon-coplane structure of each aromatic diamine derivatives were proven.We prepared the TiO₂ nanocrystalline electrode which sensitized by synthesizeddyes and assembled the solar cells. We find that the cells have very strongphotoelectric current response in the 400nm-600nm visible light region after TiO₂nanocrystalline electrode was sensitized. The highest cell effiency was 0.033％, short-circuit current(J_sc) was 0.23mA/cm², Open Circuit Voltage(V_oc) was300mV, fill factor was 0.48, IPCE(400nm) was 45％under 90mW/cm² light intensity.