A cascade energy band structure enhances the carrier energy in organic vertical-type triodes

Organic vertical-type triodes (OVTs) based on the cascade energy band structure as emitter layer are studied. The electric characteristics were dramatically enhanced while incorporating the cascade energy under current driving and voltage driving modes. The improvement is attributed to that injection carriers can obtain higher energy through a stepwise energy level. When the device has a layered structure of F16CuPC (10nm)/PTCDI (10nm)/pentacene (100nm) in emitter, it exhibits a common-base transport factor of 0.99 and a common-emitter current gain of 225 under current driving mode and exhibits a high current modulation-exceeding −520μA for a low collector voltage of −5V and a base voltage of −5V and the current on/off ratio of 103 under voltage driving mode. Furthermore, we realized first organic current mirror that exhibited out/in current ratio of 0.75 and output resistance of 105Ω by using the OVTs.