New Thick Film Functional Devices

The development of thick-film functional devices having oscillation, negative resistance, switching, memory and so on has been needed. New non-volatile memory devices manufactured of Nb 2 O 5 -based thick-film have now been created. The thick-film devices have been prepared by using common thick-film technology such as screen printing, drying and firing. The characteristics and the operation of the devices are as follows: When a dc voltage is applied to the devices, rapid resistance change, so called switching effect, occurs. The devices have low resistance state. Even when the voltage is removed completely, the devices do not return to high resistance state and keep low resistance state. However, when alternating voltage is impressed upon the devices, the low resistance state goes to the high resistance state. The recovery time of the resistance state depends upon the frequency of applied ac voltage. The higher frequency voltage that is applied, the sooner the recovery time becomes. The threshold voltage exponentially increases with higher frequency of an applied ac voltage. In addition to the memory effect, the Nb 2 O 5 -based thick-film devices have a switching and oscillation characteristic.