Nonvolatile ZnO-based Ferroelectric Field Effect Transistors for Active-Matrix Organic Light-Emitting Diode Display

The active-matrix organic light-emitting diode (AMOLED) is an energy efficient display technology due to its nonvolatility. However, the complex circuit structure obstructs its performance improvement. Here, ferroelectric field effect transistors (FeFETs) consisting of a BiFeO3 (BFO) ferroelectric gate layer, a ZnO semiconductor channel layer, and a La0.6Sr0.4MnO3 bottom-gate electrode were fabricated. A large OFF/ON resistance ratio ( $\sim {4}\times {10}^{{3}}$ ) was obtained, and the carrier accumulation or depletion at the ZnO/BFO interface owing to the ferroelectric field effect was confirmed by Hall measurements. Based on the high performance ZnO-based FeFET, a simplified AMOLED pixel circuit was designed and experimentally verified. The estimated aperture ratio was improved greatly from 28% to 37%. Furthermore, the operation speed of the FeFET could be as fast as 5 ns. These findings are of great significance in developing high performance AMOLED display devices.