Construction And Properties Of Van Der Waals Heterostructures Based On γ-GaSe Sliding Ferroelectricity

Ferroelectrics have broad application prospects in functional electronic devices,they have attracted extensive attention from researchers since their discovery in the last century.The two-dimensional interlayer sliding ferroelectricity has the property of out-of-plane polarization,which can realize ultrathin ferroelectricity at room temperature.The sliding ferroelectricity is great significant for the preparation of low power consumption and miniature optoelectronic devices.In this paper,ferroelectric field effect transistor devices were fabricated mainly based on the sliding ferroelectric properties ofγ-GaSe,exploring the storage and photoelectric characteristics at room temperature.What’s more,the shielding of ferroelectric polarized charges by photogenerated carriers was expounded.It can realize the shielding and erasing of ferroelectric polarization signals.The specific work of this paper is as follows:（1）The optoelectronic properties of the two-dimensional sliding ferroelectric materialγ-GaSe were studied,γ-GaSe andγ-GaSe/Mo S₂photodetectors were prepared respectively,and their absorption characteristics at 450 nm were tested.The photoresponsivity,external quantum efficiency and specific detectivity of theγ-GaSe photodetector are 0.02 A W^-1,5.4%and 9.41×10~7Jones under the laser with a wavelength of 450 nm.However,the photoresponsivity,external quantum efficiency and specific detectivity ofγ-GaSe/Mo S₂photodetector are 25.1 A W^-1,6914.3%and 7.54×10¹⁰Jones under 450 laser,respectively.Sinceγ-GaSe and Mo S₂ form a p-n junction structure,the separation efficiency of carriers is greatly improved.Therefore,its photoresponsity,external quantum efficiency and specific detectivity increased by three orders of magnitude,confirming thatγ-GaSe have excellent photoresponse characteristics.（2）A number of ferroelectric field effect transistor devices with a ferroelectric gate dielectric layer and a single-layer graphene as the channel layer was prepared,and its storage characteristics were tested at room temperature,its channel resistance had a large on-off ratio in different polarization states.Besides,after repeated polarization1000 times,it still maintain good ferroelectric retention properties.Multiple devices prepared show similar electrical properties,showing good repeatability.Verification the feasibility ofγ-GaSe as a ferrodielectric layer was investigated.（3）The photoelectric characteristics of the device was studied.Due to the shielding effect of photogenerated carriers on the bound charge,it can well realize the shielding of ferroelectric polarization,which providing a new idea for the development of novel high-performance non-volatile ferroelectric memory.