Memory effects in black phosphorus field effect transistors

TL;DR

This paper demonstrates black phosphorus field effect transistors that utilize hysteresis caused by intrinsic defects for non-volatile memory applications, achieving over 200 cycles of endurance and 30 minutes of data retention.

Contribution

It introduces a method to use defect-induced hysteresis in black phosphorus transistors for non-volatile memory, with enhanced stability using a protective polymer layer.

Findings

Hysteresis enables charge trapping for memory storage.

Memory devices show endurance over 200 cycles.

Retention time exceeds 30 minutes.

Abstract

We report the fabrication and the electrical characterization of back-gated field effect transistors with black phosphorus channel. We show that the hysteresis of the transfer characteristic, due to intrinsic defects, can be exploited to realize non-volatile memories. We demonstrate that gate voltage pulses allow to trap and store charge inside the defect states, which enable memory devices with endurance over 200 cycles and retention longer than 30 minutes. We show that the use of a protective poly (methyl methacrylate) layer, positioned on top of the black phosphorus channel, does not affect the electrical properties of the device but avoids the degradation caused by the exposure to air.