Fused Ring Small Molecules And Polymers:Design,Synthesis And Photovoltaic Properties

In recent years,more and more scientists have begin to pay attention to the structure of bulk heterojunction(BHJ)cell.The main advantage is that it can be converted into electricity by means of solution processing,and the cost is low.Organic solar cells(OSCs)is one of the most important batteries.Organic solar cells typically use a sandwich structure.The battery structure is composed of transparent electrode/organic active layer/metal electrode.One of the most core part is organic active layer.Organic active layer is formed by donor and acceptor materials.The donor material is constructed by electron donor cell(D)and electron acceptor unit(A).The average molecular weight is larger,acceptor materials include traditional fullerenes,but currently non-fullerenes are also popular.The transparent electrode is most commonly used in flexible substrate with conductive material or non-flexible oxide(ITO)conductive glass.Metal electrodes are usually silver,gold and aluminum.The research on fullerenes has been very mature in the research on the battery of heterogeneous junction.In the last two years,scientists have turned to the exploration and research of non-fullerenes.Fullerenes have some insuperable weaknesses:the complex synthesis,poor solubility,difficult adjustment of bandgap and weak light absorption,which are caused by the large ring,restrict its wide application.However,the non-fullerenes have the characteristics of simple synthesis,good solubility,easy adjustment and wide absorption.This thesis mainly deals with two aspects:1.Design a new type of thick ring receptor material(carbon oxygen bond)to prepare the battery and test its photovoltaic performance.A-D-A non-fullerene acceptor COi6IC,COi6FIC and COi6DFIC were obtained by adding a different end-based fluorine atom structure at the end of the 6-ring unit COi6.Preparation with the FTAZ battery components,optimized FTAZ:COi6IC,FTAZ:COi6FIC and FTAZ:COi6DFIC energy conversion efficiency of 8.25%,9.12%and 8.34%,research shows that the effect of fluorine atoms due to chemical bonds,can adjust the molecular level,make more match to the acceptor level;It can also expand absorption and increase current.And improve the PCE.2.The new structure materials were designed to be extended to 10 rings by pentacyclic imide to explore their molecular structure and device performance.Main design based on around heptyl because ketone was synthesized fused ring acceptor units,5-(2-octyldodecyl-4h-thieno[2',3':4,5]thieno[3,2-c]thieno[2',3':4,5]thien o[2,3-e]azepine-4,6(5H)-dione(TTA),based on this acceptor units with the same d onor BDT preparation for two new conjugate copolymer PTTABDT and PBTT ABDT.Their thermal,optical,electrochemical and photovoltaic properties were studied.