Synthesis And Properties Of Solution Processed Cathode Interfacial Materials With Conjugated Structure

Water/alcohol conjugated polymers and oligomers have been widely applied in optoelectronic devices for their excellent optoelectronic properties and good solubility. By inserting a cathode interlayer between the cathode and the active layer can reduce the work function of the cathode, thus quasi ohmic contact can form between the cathode and the active layer to improve the ability of electron transportation in OSCs. Based on water/alcohol soluble interfacial materials in the OSCs device have shown good performance, in order to understand the introduction of the interfacial material influence on device performance mechanism more comprehensive, the article design and synthesis of a kind of new structure water/alcohol soluble oligomers interfacial materials, and research for the influence of OSCs device photovoltaic performance.In this thesis, a series of fullerene derivatives materials named as FPNOH, FPP, FPNBr were designed and synthesized. Through researching of the UV-visible absorption spectrum of target product, we found that the absorption spectrum of these materials have shown independ on the polarity of the functional groups. After testing the contact angle of these three materials, we found that different polar functional groups show different hydrophilic properties. The electrochemical properties of the three materials were studied by cyclic voltammetry(CV) method. The calculated LUMO level of these materials were well-aligned with the LUMO energy level of PC71 BM, suggesting the great potential as efficient cathode interlayer for these materials in OSCs.In chapter 3, FPNOH was developed to apply as electron-collecting interlayer for high efficiency inverted OSCs with active blends of PTB7:PC71BM. The champion PCE value of 8.34% was achieved, and 3.1-fold enhancement was observed compared with the reference devices based on bare ITO electrode(2.69%). For investigating the feasibility of the FPNOH in different PSCs, P3HT/ICBA as active layer in inverted OSCs was also fabricated. The best PCE value of 8.34% was achieved. To depth studies the electron transport mechanism of FPNOH, implying sufficient charge extraction ability of FPNOH interfacial layer. Alcohol soluble fullerene derivative FPP has been applied as catode interlayer for conventional OSCs device, which configuration was ITO/PEDOT: PSS/PTB7:PC71BM/FPP/Ag, the best PCE value of 6.42% was achieved. This study suggested that FPP with excellent electron extraction ability and unique solubility is very promising interfacial material for OSCs.In chapter 4, a kind of alcohol soluble based on different conjugate skeleton interfacial material named as Tr6 FPEOH, PDINOH, DPPNOH were designed and synthesized, and the core-shell structure of the materials can be helpful to study the interface control influence on photovoltaic performance of OSCs device. By researching the photophysical and electrochemical properties of these materials, suggesting that conjugate skeleton have deep affect on their photophysical and electrochemical properties.