Design, Sythesis And Properties Of Polymers Solar Cells Materials Based On [1,2,5]Thiadiazolo [3,4-c]Pyriding

In order to improve the photovoltaic performance of the polymer solar cells, the photovoltaic polymer solar cells materials were obtained by matching the absorption spectrum with the solar light and with narrow band gap, In this paper, a series of conjugated polymers were designed and synthesized, their structures were characterized, and the photovoltaic properties of some materials were studied. Specific content as follows:1) 4,7-bis?5-thiophen-2-yl?-[1,2,5]thiadiazolo[3,4-c]pyriding based copolymer ?P1? has been synthesized by Suzuki coupling polymerization reaction. The compounds synthesized have good solubility and excellent film forming properties. P1 polymer possess broad absorption range ?450-650 run?, lower HOMO levels (E_HOMO=-5.71 eV) and a narrower optical band gap (E_g^opt= 1.76 eV).2) Two new conjugated polymers containing 3,6-bisbromo-9-?4-?bis?9-4?octyloxy?? phenyl?benzo?-9-carbazol)methyl)phenyl)-9-hydrogen carbazole ?M3??3,6-bisbromo-9-?4-?bis?N,N-bis?4-?octyloxy??phenyl?anilino?methyl?phenyl)-9-hydrogen carbazole ?M4??2,7-bis?1,3,2-Dioxaborolane,4,4,5,5-tetramethyl-2-?2-propen-1-yl?-?4?octyloxy??phenyl?carbazol ?M5? donor units and 4,7-bis?5-thiophen-2-yl?-[1,2,5]thiadiazolo[3,4-c] pyriding acceptor unit, P2 and P3 were synthesized by Suzuki coupling polymerization, and have good solubility, excellent film forming properties. The polymers possess broad absorption range ?450-650 nm?, the lower HOMO levels as -5.65 eV and -5.75 eV respectively and with narrow optical band gap as 1.83 eV and 1.73 eV respectively.3) A series of conjugated polymers with 2,7-bis?1,3,2-Dioxaborolane,4,4,5,5-tetrameth-yl-2-?2-propen-1-yl?-?4?octyloxy??phenyl?carbazol as electron-donor ?M4? unit and 4,7-bis?5-thiophen-2-yl?-[1,2,5]thiadiazolo[3,4-c]pyriding?3,6-bis?5-bromo-2-thienyl?-2,5-bisn-octyl-1,4-diketopyrrolopyrrole as electron-acceptor ?Ml? unit was designed and synthesized. The polymers have good solubility and excellent film forming properties and exhibited broad absorption range ?500-700 nm?, the lower HOMO levels as -5.31,-5.22,-5.31 and-5.35 eV respectively and with narrow optical band gap as 1.65,1.61,1.64 and 1.67 eV respectively.4) The bulk hetero junction solar cells were made with P4 and P5/pc61bm ?1:2, w/w?, and among this photovoltaic devices, the P4 showed better photovoltaic performance, the maximum open circuit voltage (V_OC) is 1.12 V, with a short-circuit current (J_SC) as 745 ma.cm^-2 and photoelectric energy conversion efficiency ?PCE? of 2.40%.