| Vertical-type organic thin film diodes are fabricated by vacuum vapor deposition and magnetron sputtering in this paper,the samples are encapsulated by PI encapsulation,epoxy resin encapsulation,CuPc film and epoxy resin composite encapsulation,CuPc and PI films composite encapsulation separately.The electrical properties of encapsulated and unencapsulated diodes are compared in a period of time.The electrical stability and working reliability of devices were investigated in indoor environment to parse the effect of encapsulation and method to deal with the practicability of organic thin film device.So as to increase the possibility of its practical application.Experimental results show that the initial performances of encapsulated and unencapsulated devices were similar.With the passage of time,the unencapsulated device tended to be insulated,Al electrode was oxidized into non-conductive aluminum oxide,and the current was very small in the device.Although PI encapsulation could protect organic devices,the performances of the devices were decreased greatly in the packaging process.It can be seen in the result of epoxy resin encapsulation,this method had a great impact on the device during encapsulation,and could protect the device for a while.The rectifying characteristics of devices would be destroyed eventually by epoxy resin,and diodes turned to resistors without the impact of environment.The device encapsulated by CuPc film and epoxy resin declined as well,but it was less affected by epoxy resin,film encapsulation could protect devices from epoxy resin,but the influence of epoxy resin can't be eliminated completely.CuPc and PI films composite encapsulation has a strong protective effect on devices.The device was unaffected in the packaging process,and PI film could protect devices well.The threshold voltage of device rose slowly,from 0.28V to 0.4V,the slope is 1.65×10-2.The output resistance tended to be stable,it is 1.1×104?.The conductivity fell to 2.4×10-8S/cm,but the declining trend was slowing down.Devices were tested in the condition of high humidity,the unencapsulated device couldn't work,there would be a performance recovery after test,but it impacted devices greatly,which would accelerate the damage of the environment.The diode encapsulated by CuPc and PI films could work well still,the performance of it did not change much in the normal environment,and it is affected by humidity hardly. |
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