Synthesis And Application Of Cathode Interface Materials Based On Water/alcohol Soluble Porphyrin Derivatives In Polymer Solar Cell Devices

Polymer solar cells(PSCs) have attracted considerable attention in recent years due to their unique characteristics, such as low cost, light weight and potential applicability to flexible and large-area devices. PSCs usually adopt a basic architecture composed of a thin layer of organic semiconducting material sandwiched between two electrodes. It is therefore important to control the organic/electrode interface to optimize charge-injection/ extraction and improve the device performance. Porphyrins have extensively π-conjugated systems which were contributed to electron transfer from donor unit to acceptor unit, and have high molar absorption coefficients in light absorption, and their properties can be easily tuned via synthetic modifications for the periphery or by metal insertion into the cavity of porphyrin. Porphyrins have attracted more and more attention due to its physical and chemical properties. In this thesis, the studies demonstrated are side chain modifications in water/alcohol soluble porphyrin and metal porphyrin molecules to enhance their interface modification capability in polymer solar cells.In chapter 2, we firstly synthesized porphyrin molecules, and then sidechain-amino-functionalized porphyrin(Por-N) and porphyrin quaternary ammonium(Por-NBr) was prepared. Thermal properties, UV-vis absorption properties, electrochemical characteristics and carrier mobility were systematically studied for Por-N and Por-NBr. When used as interface modification layer in PCE10 based OPVs, the choice of porphyrin quaternary ammonium had a great improvement on the device performance.In chapter 3, metal porphyrin molecules based on zinc and copper as the center of porphyrin were synthesized. Then side- chain-amino-functionalized metal porphyrin and metal porphyrin quaternary ammonium was prepared, which showed good thermal properties. Counter-ions in side chain have no influence on the UV-vis absorption and molecular orbital level for porphyrin. When used as interface modification layer in PCE10 based OPVs, the choice of amino-functionalized coppor porphyrin had a great improvement on the device performance.