Synthesis Of Crosslinkabel Hole Transport Polymers And Green/Blue-light Emitting Conjugated Polymers And Their Properties

Since the Japanese scientist Shirakawa Hideaki discovered that polyacetylene is conductive in 1977,conductive polymers have attracted many scientists to study with their outstanding photoelectric properties.Due to the conjugate nature of such material structures,it is capable of transporting charge,excited light,and thus can or may be used in many electronic or optoelectronic devices,such as polymer light-emitting diodes,photovoltaic cells,field effect transistors,and the like.Potential application prospects and a wide range of applications have prompted scientists to compete in the study of such photoelectrically active conjugated materials.From the perspective of material workers,this thesis designs and synthesizes a series of new photopolymers based on the problems to be solved in the research of polymer photovoltaic materials,and studies their photoelectric properties.The main contents are as follows.We designed and synthesized photo-crosslinkable hole transport materials for perovskite solar cell,which has rarely been reported.The current efficiency of perovskite solar cells is close to the theoretical value,and the bottleneck lies in stability.The hole transporting material is indispensable in the perovskite solar cell,but the cross-linking type of hole transporting material is less,and thermal crosslinking is generally employed.It is well known that perovskites are not heat-resistant,and the use of styrene for cross-linking actually requires a very high temperature,and even at 180 degrees,the degree of cross-linking is limited,and is difficult to distinguish in infrared.To this end,we synthesized two hole transporting materials with a cinnamate side chain,the main chain of which is composed of carbazole and triphenylamine.It is characterized by efficient cross-linking at room temperature and infrared discrimination.By electrochemical measurement,the HOMO energy levels of the two materials are all around-5.20 eV,which is in accordance with the expected design and is suitable for the hole transport layer of perovskite solar cells.The polymers PTPA-co-CzC6Cn and PTPA-co-TPAC6Cn are very promising hole transport materials.We designed and synthesized two kinds of heat-crosslinking hole transporting materials with silicon in the main chain.It is characterized by the absence of noble metal catalysis and the use of the Wurtz reaction,the purity of the product is very high.Although the molecular weight is not high,a tough film can be obtained by thermal crosslinking at 120 degrees.The introduction of silicon improves the anti-aging and fission resistance of the material during thermal crosslinking.The electrochemically determined HOMO levels of the two materials were-5.40 eV and-5.6 eV,respectively.We designed and synthesized a highly efficient and stable pure green light material for use in high resolution fluorescent displays.The copolymer of hydrazine and benzothiadiazole is considered to be an excellent green light material with high efficiency and good stability,but actually yellowish green.For the sake of excellence,we have synthesized polyfluorene with benzothiadiazole in side chains.The polyfluorene of thiadiazole gives a series of CIE-adjustable green-emitting polyfluorene materials(PFPBtPtBu0.5-co-PFO to PFPBtPtBu30-co-PFO).Its OLED performance is also superior to conventional backbone copolymers.Compared with 30%copolymer of benzothiadiazole,the side chain type has a turn-on voltage of 3.4 volts,a maximum brightness of 5667 cd/m~2,a maximum efficiency of4.44 cd/A,and a CIE of(0.32,0.52);The type has a turn-on voltage of 3.9 volts,a maximum brightness of 7090 cd/m~2,a maximum efficiency of 3.70 cd/A,and a CIE of(0.44,0.54).The side chain polymer we designed and synthesized has a slightly lower brightness,and the others are larger than the main chain type.We pioneered the introduction of chromophores on poly(N-vinylcarbazole)(PVK)by Suzuki reaction,which is characterized by:1.It uses PVK,which does not contain long-chain alkyl groups but is soluble.The polymer,PVK,is one of the few practical stable conjugated polymers.2.By brominating PVK and then introducing chromophores to form energy transfer,this synthesis method is simple and efficient,and has not been reported.A conjugated group grafted material(PVK-gf-DPE)was obtained by introducing stilbene at the 3 or 3,6 position of PVK,and its optical properties were investigated.The photoluminescence emission peak of PVK-gf-DPE was red shifted from 409 nm to 421 nm of PVK,and the fluorescence quantum yield was increased from 8.8%to 12.1%,indicating that the introduction of a conjugated group can change the luminescent properties.Relevant synthetic work experience has laid the foundation for the realization of red,green and blue-emitting polymers without long chain solubilizing groups.