Abstract :
Summary form only given. The electrical characteristics of thermally evaporated Perylene - 3, 4, 9, 10 tetra carboxylic acid-bis methylimide (DMP) are studied. We have made In / DMP/ITO, Ag /DMP/1TO and Au /DMP /ITO devices by vacuum thermal evaporation of DMP and metal (In, Au and Ag) on chemically cleaned glass slides covered with suppered NESA (ITO) substrate. The evaporation of DMP and metal were carried out during the same pump down at a back ground pressure of less then 2 x 10/sup -5/ torr. The I-V characteristics were taken using the HP I-V meter and the Capacitance measurement were done with 4274 HP LCZ meter at frequencies ranging from 100 hz to 100Khz. A number of parameters permittivity, electron mobility, room temperature electron concentration, total trap concentration and room temperature conductivity is evaluated on the basis of space charge limited conduction. I-V relationship seems to indicates a frenkel -pool mechanism. From I-V and C-V measurements , it is confirmed that Au-DMP ITO-DMP and In-DMP interface form the schottky barrier while the Ag-DMP interface form the ohmic contact. The diode ideality factor and reverse saturation current of all the devices have been also calculated. We have also calculated the schottky barrier height for the Au/ DMP/ ITO device by thermionic emission method and Internal photoemission (IPE) method. It is emphasized that The IPE measurement gives accurate direct determination of barrier height. The results on I-V and C-V measurements are discussed in details.
