The Preparation And Properties Of Ultrathin Silver-based Film For Organic Photodetector

In recent years,low-power,low-cost,flexible organic photodetectors have developed rapidly,and have a wide range of applications in artificial vision,night vision,biomedical,image sensing,and other fields,and are expected to become a new generation of commercial photodetectors.In organic photoelectric imaging devices,the organic photodetector preparation process should be compatible with the Complementary Metal Oxide Semiconductor(CMOS)process to achieve monolithic integrated manufacturing of the device.For monolithic integrated organic photodetectors,incident light is transmitted into the active layer through the top electrode to produce a light response.Therefore,the top electrode needs to be designed to be highly transparent and highly conductive.Based on the demand for transparent electrodes for organic photoelectric imaging devices,this thesis studies the preparation and performance of ultra-thin silver-based films for organic photodetectors,and the main research contents and results are as follows:(1)In this thesis,ultra-thin Ag-Cu films were prepared by magnetron sputtering,the photoelectric properties of the films were evaluated,and the device was verified.Through the surface morphology characterization and work function analysis of the Ag-Cu film,it is confirmed that the work function of the Ag-Cu film is comparable to the work function of the Ag film,which can meet the energy level matching conditions of the device and has a smaller surface roughness than that of the pure Ag film.The influence mechanism of magnetron sputtering time and Cu doping amount on the photoelectric properties of ultra-thin Ag-Cu films was explored,and the transparent top electrode of the organic photodetector was selected as the transparent top electrode of the organic photodetector,and the performance test of the device was carried out,and the J-V characteristic curve confirmed that the device was a diode-type organic photodetector.At a bias of-0.5 V,the specific detection rate of the device can reach 10¹² Jones.(2)MoO₃/Ag-Cu/HfO₂ multilayer transparent electrode film was designed and prepared,and the device was verified.The characterization and analysis of the surface morphology of the multilayer film confirmed that the surface roughness was slightly lower than that of the Ag-Cu film.The influence mechanism of MoO₃ and HfO₂ thickness on the photoelectric properties of MoO₃/Ag-Cu/HfO₂ multilayer films was explored,and reasonable MoO₃ and HfO₂ thicknesses were optimized.Finally,an organic photodetector device was prepared based on the multilayer transparent conductive film.Device performance tests show that the diode-type organic photodetector has a specific detection rate of 10¹² Jones in the visible light range at a bias voltage of-0.5 V,which is better than the specific detection rate of the Ag-Cu device.(3)The preparation process and photoelectric properties of ultra-thin Ag-Mo films and their performance as transparent electrodes are further explored.The surface morphology characterization and work function analysis of Ag-Mo film confirmed that the work function of Ag-Mo film satisfies energy level matching,and the surface roughness is slightly lower than that of pure Ag film.The effect of magnetron sputtering time and Mo doping amount on the photoelectric properties of ultra-thin Ag-Mo films is studied,and the Ag-Mo films with outstanding performance are selected as transparent electrodes for organic photodetectors.Finally,the device was I-V tested and spectrally tested,and at a bias of-0.5 V,the specific detection rate of the diode-type photodetector reached 10¹² Jones,which was better than the specific detection rate of the ultra-thin pure Ag device.