Synthesis Of Benzo[1,2-b:4,5-b′]diselenophene Type Polymer And Pyrazine Type Polymer For Bulk Heterojunction Polymer Solar Cells

Polymer solar cells(PSCs) have attracted remarkable attention recent years due to their advantages of low cost, light weight, and easy fabricatio n. There are two kind of blending system in the bulk heterojunction organic solar cells. One is polymer / fullerene blend and another way is all polymers blend. The power conversion efficiency of single junction has reached 10.08% and tandem junction has exceeded 11 % in polymer/fullerene blend. O n the other hand, the PCE of all polymer blend BHJ solar cells is exceeding 6% with N2200 as an accepter material. A key method to improve the power-conversion efficiency is to explore active materials which possess board spectrum absorption, relatively deep HOMO energy level and good solubility in both blend system.(1) In the polymer/fullerene solar cell system, two new D-A type polymers(PBDSe-DPP, PBDSe-IDT) have been designed to explore new ideal semiconducting polymers. Polymers were synthesized by conjugating acceptor unit diketopyrrolopyrrole/isoindigo to a donor unit Benzo[1,2-b:4,5-b′]diselenopheneusing through a Stille Coupling Reaction. The thermal, optical, electrochemical, photoelectric and photovoltaic properties of the two new polymers were studied systematically. Limited by its media solubility we obtained decent power conversion efficiency of 3.7% and 2.5% respectively.(2) Three donor materials were designed and synthesized by changing the backbone unit of PTQ1. The polymers containing benzene, thiophene, pyridine backbone unit which show different energy level and band gap behaved different device performance. We have investigated the polymer’s thermal, optical, electrochemical and photovoltaic properties. With three different energy level donor materials, We studied the device performance blended with N2200 as the accepter and conversion efficiency for the three materials are P1(0 %), P2(2.91 %), P3(2.98 %).