Demonstration of Microwave Harvesting Through Pyroelectricity in Cryogenic Conditions: A Quantum-to-Experimental Approach

In this letter, we present a comprehensive study of a planar field effect transistor (FET) with a graphene/ferroelectric channel on high-resistivity silicon substrate, able to convert the incident microwave power into a pyroelectric voltage in cryogenic conditions down to 100 K. The FET is based on a graphene monolayer/zirconium-doped hafnium oxide (HZO) heterostructure, being the graphene perforated with a matrix of nanoholes. This choice has two aims: 1) to create a bandgap in the graphene monolayer and 2) to reduce graphene's thermal conductivity, thereby promoting the generation of a pyroelectric current. Starting from quantum simulations to assess the electrical behavior of the channel, we measured in a cryogenic setup a maximum detected pyroelectric voltage of about 18 mV at 2 GHz and at 100 K. Moreover, the detected transient pulses fit in to solitons, which are typical for thin film ferroelectrics.