Ferroelectric field‐effect transistors (FeFETs) employing graphene on inorganic perovskite substrates receive considerable attention due to their interesting electronic and memory properties. They are known to exhibit an unusual hysteresis of electronic transport that is not consistent with the ferroelectric polarization hysteresis and is previously shown to be associated with charge trapping at graphene–ferroelectric interface. Here, an electrical measurement scheme that minimizes the effect of charge traps and reveals the polarization‐dependent hysteresis of electronic transport in graphene–Pb(Zr,Ti)O3FeFETs is demonstrated. Observation of the polarization‐dependent conductivity hysteresis is important for the fundamental understanding of the interplay between the ferroelectric polarization and charge carriers in graphene. It is also important for practical memory applications because this hysteresis emulates the operation of nonvolatile memories and reveals the range of ON and OFF currents that can be achieved in long term data storage. It is demonstrated that this measurement scheme can be used to optimize the memory performance of graphene–PZT FeFETs that can exhibit nonvolatile time‐independent ON/OFF ratios of over 5. The described measurement technique can potentially be used in the studies of kinetics of charge trap dissipation, polarization‐dependent properties, and memory performance of FeFET devices comprising other 2D materials and various ferroelectric substrates.
Ferroelectric (FE) devices are conventionally switched by an application of an electric field. However, the recent discoveries of light–matter interactions in heterostructures based on 2D semiconductors and FE materials open new opportunities for using light as an additional tool for device programming. Recently, a purely optical switching of FE polarization in heterostructures comprising 2D MoS2and FE oxide perovskites, such as BaTiO3and Pb(Zr,Ti)O3(PZT), was demonstrated. In this work, it is investigated whether this optical switching has a practical value and can be used to improve functional characteristics of MoS2‐PZT FE field‐effect transistors for nonvolatile memory applications. It is demonstrated that the combined use of an electrical field and visible light improves the nonvolatile ON/OFF ratios in MoS2‐PZT memories by several orders of magnitude compared to their purely electrical operation. The memories are read at zero gate voltage (
- NSF-PAR ID:
- 10359977
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Electronic Materials
- Volume:
- 7
- Issue:
- 5
- ISSN:
- 2199-160X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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