Research On The Application Of Carbon Quantum Dots In Doped OLED Devices And P3HT:PC₆₁BM-Based Photovoltaic Devices

In the past decade,the theoretical research and commercial development of organic optoelectronic devices have made great progress.Organic optoelectronic semiconductor material has the outstanding advantages of wide source of raw materials,simple manufacturing process,low toxicity and so on,which can be applied to various organic optoelectronic devices according to different needs.However,organic optoelectronic devices also have obvious shortcomings,For example,Organic Light Emitting Diode?OLED?devices have many problems such as low performance,short life,unstable blue fluorescent materials,and imperfect device mechanism theory;Organic Solar Cell?OSC?devices have problems such as weak light absorption,poor stability,and low power conversion efficiency.Based on the above problems of organic optoelectronic devices,the thesis focuses on improving the performance of organic light-emitting diode based on doped system and organic solar cell based on P3HT:PC₆₁BM system.The specific research work is as follows:The thesis introduces the research status of organic light emitting diode and organic solar cell,and analyzes the shortcomings of current research.The working mechanism and related physics of organic light emitting diode and organic solar cell were described.Carbon Quantum Dots?CQDs?,a fluorescent material,were synthesized by microwave assisted method and successfully applied to blue,yellow,red and white organic light-emitting diodes,and the optical and electrical properties of the device have been characterized.The test results show that the introduction of carbon quantum dots can effectively improve the brightness and current density of the device,and reduce the opening voltage of the device.In addition,the carbon quantum dots can also control the position of composite luminescence;Combined with the degradation phenomenon in the organic light emitting diode devices in the experiment,the influence of the introduction of carbon quantum dots on the stability of the device was analyzed.The experimental results show that the high concentration of carbon quantum dots can make the surface of organic layer form bumps.These bumps form dark spots under the action of external electric field,which eventually leads to the burnout of the device.Carbon Quantum Dots are simultaneously introduced between the active layer and the anode buffer layer of the organic solar cell and between the active layer and the cathode,and the performance of the devices were tested and analyzed.The test results show that the introduction of carbon quantum dots can greatly improve the performance of the device,which is due to the improvement of carrier transport and collection efficiency due to the dual-interface modification of carbon quantum dots.In addition,the introduction of carbon quantum dots can improve the optical capture ability of the device.A flexible organic solar cell based on P3HT:PC₆₁BM system was successfully prepared using a PET substrate,and the effects of the active layer and the anode buffer layer on the device performance under different conditions were studied in detail.The test results show that the short circuit current,open circuit voltage,filling factor and energy conversion efficiency of the optimized device are 12.00mA/cm²,0.53V,38%and 2.13%,respectively.