Synthesis And Photovoltaic Characterization Of Polymers Based On Dimensional Polycyclic Benzothiophene Derivatives

With traditional energy sources(coal, oil) gradually declined, the people's demand for energy is growing. It is become increasingly prominent to seek and develop new and renewable energy sources. The use of solar energy is an effective way to solve the energy problems of mankind, while the solar cell is one of the effective way to use of solar energy. Polymer solar cells(PSCs) with its excellent characteristics receives much concern, such as relatively lower raw material prices, high flexibility, light weight, materials design and modification easier. Therefore, the design and synthesis of excellent performance of polymer solar cell materials has a very important significance to the development and utilization of solar energy.This paper by means of an electron donor dithieno[2,3-d:2?,3?-d?]benzo[1,2-b:4,5-b?]dithiophene(DTBDT), benzo[1,2-b:4,5-b']dithiophene(BDT) modification, synthesized conjugate with a larger surface and the length longer dimensional polycyclic electron donor unit 5,10-bis(4,5-didecylthien-2-yl)dithieno[2,3-d:2?,3?-d?] benzo[1,2-b:4,5-b?]dithiophene(DTBDT-T), 4,8-bis(4,5-di-octylthiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene(BDT-T), 4,8-bis(triisopropylsilyethynyl)benzo[1,2-b:4,5-b']dithiophene(BDT-TIPS). Respectively, with DTBDT-T, BDT-T, BDT-TIPS for the donor cell, and selected the excellent performance of the electron acceptor units by Stille polymerization synthesized a series of Donor-Accpter(D?A) type conjugated polymers, and its performance was tested. The main contents as follows:1. Chapter II, Introduced alkylthiophene in the middle of the DTBDT benzene obtain an excellent performance of a two-dimensional structure unit DTBDT-T. Selecting some receptor units and using synthetic electron donor unit, through Stille coupling reaction obtained four kinds of conjugated polymers, named as PDTBDT-DTBTC8, PDTBDT-DTFBTC8, PDTBDT-DTBTC12, PDTBDT-DTFBTC12. These polymers have good thermal stability, and can be dissolved in common organic solvent, such as toluene and o-dichlorobenzene. With polymer PDTBDT-DTFBTC8 as donor materials, and PC71 BM as acceptor materials prepared the photovoltaic device, its energy conversion efficiency is 7.12 %, the short-circuit current is 15.10 mA/cm2 and the open circuit voltage is 0.73 V.2. Chapter III, In the 4,8-position of the BDT introduction alkylthiophene and triisopropylsilyethynyl(TIPS) side group, The BDT derivative electron donor unit with a two-dimensional structure has been synthesized. Use of synthesized BDT derivatives and N,N?-(2-hexyldecyl)isoindigo(IDC16) by Stille coupling reaction obtained polymer based on BDT derivatives, which were named as PBDT-T-IDC16 and PBDT-TIPS-IDC16. Their electrochemical, absorption spectrum, emission spectrum, thermal properties were tested. With the polymer PBDT-T-IDC16 as donor materials, PC71 BM as acceptor materials prepared the photovoltaic device, its the energy conversion efficiency is 2.41 %, the short-circuit current is 4.55 mA/cm2 and the open circuit voltage is 0.89 V.3. Chapter IV, With 4,8-bis(triisopropylsilyethynyl)benzo[1,2-b:4,5-b']dithiophene(PBDT-TIPS) as electron donor unit and benzo[1,2,5]thiadiazole(BT), 5,6-bis-dodecyloxyyl-benzo[2,1,3]thiadiazole(BTC12), 5-octyl-thiophene[3,4-c]pyrrole-4,6-dione(TAC8), 5-(2-hexyldecyl)thieno[3,4-c]pyrrole-4,6-dione(TAC16) as electron acceptor unit, four conjugated polymers with D?A type were obtained through Stille polymerization reaction, respectively. It named as PBDT-TIPS-BT, PBDT-TIPS-BTC12, PBDT-TIPS-TAC8, PBDT-TIPS-TAC16. Their electrochemical, absorption spectra, emission spectrum and thermal properties were tested.