The organic semiconductor device capacitance properties of
|Course||Condensed Matter Physics|
|Keywords||Device research An organic semiconductor Negative capacitance Capacitance ratio Organic light-emitting Hole pairs EL spectra OLED Electron injection Single layer device Light-emitting layer The organic Layer Admittance spectroscopy Voltage relationship Organic surface Film FET Interface barrier Discharge process Carrier transport Luminous intensity|
Organic semiconductors are scientific research and industrial development in recent years, most research has potential application areas. The object of this thesis is the organic semiconductor device capacitance characteristics , the most important is the study of organic electroluminescent devices (OLED) capacitance - voltage characteristics and capacitance - frequency characteristics. The main contents are: device capacitance size and strength of the link between emission and its mechanism , the phenomenon of negative capacitance relationship with the luminescence mechanism of its formation , the use of the device during discharge measuring device capacitance transient methods . Includes the following two aspects: 1 . Different positions in the light emitting layer is doped with device capacitance characteristics : in the organic light emitting layer of the OLED layers at different positions , the doping concentration of the same thickness as the object of the same dye molecules , and the use of the method of measuring admittance spectroscopy study of the device capacitance - voltage (CV) and capacitance relations - frequency (CF) properties. Meanwhile, we also measured the doping device current - voltage - luminescence (IVB) and electroluminescent spectra and other optical properties. These results help us to give the OLED capacitance between the luminescence intensity , and provides the possibility of negative capacitance phenomenon , allows us to the phenomenon of negative capacitance mechanism and it is given between the light emitting devices a reasonable explanation. Further , in order to verify that we came to the conclusion , we have prepared another group of different doping concentration of the original doping device . Through the measurements of these devices , verification of the validity of the conclusions obtained earlier . (2) to establish the transient discharge process based device capacitance measurement methods : the use of different thickness of a single organic layer unipolar devices during discharge voltage - time evolution of relationships and device current - voltage characteristics analysis, combined with single layer device the equivalent circuit model and RC parallel circuit discharge theory, calculate the device capacitance - voltage relationship . Thus, we established a new research device capacitance - voltage relationship measurement method. In addition , a new method for the single device to the measured characteristic curve expressed by CV characteristic , we use the space charge capacitance capacitor to the device with the terminal voltage geometric changes in the characteristics , which were reasonably described.