Continuous-wave and Transient Characteristics of Phosphorene Microwave Transistors

TL;DR

This paper investigates the microwave performance of few-layer phosphorene MOSFETs, demonstrating their potential for high-frequency applications with favorable transient characteristics and stable DC behavior.

Contribution

It provides the first detailed analysis of the microwave and transient characteristics of phosphorene MOSFETs, confirming their viability for microwave transistor applications.

Findings

Cutoff frequency of 2 GHz and oscillation frequency of 8 GHz after de-embedding.

Gate and drain lag around 1 microsecond, indicating fast transient response.

No hysteresis or persistent photoconductivity observed in DC measurements.

Abstract

Few-layer phosphorene MOSFETs with 0.3-um-long gate and 15-nm-thick Al2O3 gate insulator was found to exhibit a forward-current cutoff frequency of 2 GHz and a maximum oscillation frequency of 8 GHz after de-embedding for the parasitic capacitance associated mainly with the relatively large probe pads. The gate lag and drain lag of the transistor was found to be on the order of 1 us or less, which is consistent with the lack of hysteresis, carrier freeze-out or persistent photoconductivity in DC characteristics. These results confirm that the phosphorene MOSFET can be a viable microwave transistor for both small-signal and large-signal applications.