Enhanced Performance of Organic Field‐Effect Transistor Memory by Hole‐Barrier Modulation with an N‐Type Organic Buffer Layer between Pentacene and Polymer Electret

Abstract

AbstractTheoretical and experimental work has revealed that a positively charged insulator layer formed by oxygen‐related defects near pentacene–dielectric interface in organic field‐effect‐transistors (OFETs) severely affects their performance. A novel OFET memory structure with an n‐type organic buffer layer at the pentacene/polymer interface is proposed. In this structure, electrons are induced on the surface of the n‐type organic layer near the interface due to the electrostatic field of the positively charged insulator and partly compensate the local positive charges at the interface, leading to a reduction in the height of hole barrier formed at the interface. On the other hand, the positive space charges will be induced in an extended region in n‐type organic layer due to the limited density of ionized donors, blocking the back transfer of holes to pentacene as a result of the thicker positively charged layer. This idea is implemented in the n‐type PTCDI‐C13‐buffered OFETs with poly(2‐vinyl naphthalene) (PVN) dielectric, in which greatly reduced P/E gate voltages, reliable P/E endurance of more than 10 000 cycles, and excellent retention time of more than 104 s with an ION/IOFF of more than 104 under a set of P/E pulses with low amplitudes and short pulses are achieved in air.