| Electrochemical polymerization films can be deposited selectively and directionally,and the structure and properties of the films can be controlled.However,due to the strong interaction between the chain segments and the quenching effect caused by charge residue,the electropolymerized films generally have no fluorescence or weak fluorescence.In the past work,our research group has developed an electropolymeric precursor molecule OCBzC,which contains eight carbazoles as cross-linking groups.The molecule can form high cross-linking light-emitting films in the process of electropolymerization.The brightness and efficiency of organic light-emitting devices?OLEDs?prepared by OCBzC can reach the level of spin-coating devices and have potential applications in OLEDs and display.In the process of preparing OLEDs thin films by traditional methods,blending method can be used to improve the quality of thin films and devices with better performance.In electrochemical methods,electrochemical copolymerization of two or more molecules can be used to adjust the structure and properties of thin films and optimize device performance.In this dissertation,focusing on the application of electrochemical copolymerization thin films in organic light-emitting devices,in order to adjust and optimize the quality and electroluminescent properties of light-emitting thin films,alkyl tricarbazole molecule and light-emitting molecule OCBzC were selected for electrochemical copolymerization.The electrochemical kinetics,the density of copolymerized thin films and the performance of related devices were systematically analyzed.And the different substituents of tricarbazole were discussed,the electrochemical behavior of triazole molecule,the properties of copolymer film and the performance of related devices and display system integration are analyzed.The main contents are as follows:?1?Study on electrochemical copolymerization of alkyl tricarbazole molecule with luminescent molecule OCBzC and its application in OLEDs.The kinetics and electrochemical behavior of alkyl tricarbazole?E-3Cz?and luminescent molecule?OCBzC?are studied.Compared with OCBzC,E-3Cz have faster diffusion rate and electron transfer rate,higher electrochemical activity and lower initial oxidation potential.The electrochemical copolymerization of alkyl tricarbazole?E-3Cz?and luminescent molecule?OCBzC?is carried out.The introduction of E-3Cz results in a significant increase in the polymerization rate and film thickness of OCBzC.The morphology of copolymerized films is optimized by adjusting the copolymerization ratio.The density of the films increases from 1.742 before copolymerization to 1.763 after copolymerization.The hole mobility increases from 4.8×10-88 cm2 V-11 S-11 before copolymerization to 1.1×10-66 cm2 V-11 S-11 after copolymerization?about 23 times higher?.The open voltage of devices fabricated by copolymerized thin films as luminescent layers decreases significantly?from 6.2 V before copolymerization to 4.3 V after copolymerization?.The maximum brightness and efficiency voltage of copolymerized thin film devices are 10.8 V and 7.2 V respectively,which are lower than those of OCBzC thin films?the maximum brightness and efficiency voltage of OCBzC thin film devices are 14.8 V and 10.8 V respectively?.?2?The effect of substituents on the electrochemical copolymerization of tricarbazole and OCBzC.The electrochemical and kinetic properties of tricarbazole molecules with different substituents are studied.Among the three molecules,the initial oxidation potential of E-3Cz,3Cz and B-3Cz increases in turn,and the electron transfer rate decreases in turn.During the electrochemical copolymerization of three triazole molecules with OCBzC molecule,the polymerization rate and film thickness of OCBzC increase significantly,and the promotion effect of E-3Cz molecule on OCBzC is the most obvious.Among the copolymer films of three molecules and OCBzC,their conductivity and density are higher than that of the monomer films of OCBzC,and the E-3Cz/OCBzC films have the highest hole mobility(1.1×10-66 cm2 V-11 S-1).Compared with OCBzC thin film devices,the leakage current of OLEDs fabricated by these three copolymer films is improved,and the opening voltage of the devices reduces from 6.2 V of OCBzC thin film devices to 4.3 V of E-3Cz/OCBzC thin film,5.3 V of 3Cz/OCBzC thin film and 5.7 V of B-3Cz/OCBzC thin film,respectively.Both E-3Cz/OCBzC and 3Cz/OCBzC thin film devices have a voltage of 10.8 V at maximum brightness,which is lower than that of OCBzC thin film devices?14.8 V?;Voltage at maximum efficiency are 7.2 V and 7.6 V,respectively,which are lower than OCBzC thin film devices?10.8 V?.?3?The application of chip-controlled electrochemical deposition technology in the preparation of patterned color films.Firstly,the device and method of selective deposition of pixels on AMOLED substrates by using chip to control the on-off of electrochemical signals and then to prepare color patterned films are proposed.At the same time,the feasibility of chip-controlled electrochemical polymerization on AMOLED substrates is verified,and the AMOLED substrates suitable for electropolymerization are explored.It is very important to find a more suitable material for metal electrode layer. |
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