Solution-Processed InAs Nanowire Transistors as Microwave Switches

Abstract

The feasibility of using self‐assembled InAs nanowire bottom‐gated field‐effect transistors as radio‐frequency and microwave switches by direct integration into a transmission line is demonstrated. This proof of concept is demonstrated as a coplanar waveguide (CPW) microwave transmission line, where the nanowires function as a tunable impedance in the CPW through gate biasing. The key to this switching capability is the high‐performance, low impedance InAs nanowire transistor behavior with field‐effect mobility of ≈300 cm2 V−1 s−1, on/off ratio of 103, and resistance modulation from only 50 Ω in the full accumulation mode, to ≈50 kΩ when the nanowires are depleted of charge carriers. The gate biasing of the nanowires within the CPW results in a switching behavior, exhibited by a ≈10 dB change in the transmission coefficient, S21, between the on/off switching states, over 5-33 GHz. This frequency range covers both the microwave and millimeter‐wave bands dedicated to Internet of things and 5G applications. Demonstration of these switches creates opportunities for a new class of devices for microwave applications based on solution‐processed semiconducting nanowires.