Two-dimensional(2D)ferroelectric materials with unique structure and extraordinary optoelectrical properties have attracted intensive research in the field of nanoelectronic and optoelectronic devices,such as optical ...Two-dimensional(2D)ferroelectric materials with unique structure and extraordinary optoelectrical properties have attracted intensive research in the field of nanoelectronic and optoelectronic devices,such as optical sensors,transistors,photovoltaics and non-volatile memory devices.However,the transition temperature of the reported ferroelectrics in 2D limit is generally low or slightly above room temperature,hampering their applications in high-temperature electronic devices.Here,we report the robust high-temperature ferroelectricity in 2D a-In2Se3,grown by chemical vapor depostion(CVD),exhibiting an out-of-plane spontaneous polarization reaching above 200℃.The polarization switching and ferroelectric domains are observed in In2Se;nanoflakes in a wide temperature range.The coercive field of the CVD grown ferroelectric layers ilustrates a room-temperature thickness dependency and increases drastically when the film thickness decreases;whereas there is no large variance in the coercive field at dfterent termperature from the samples with identical thickness.The results show the stable ferroelectricit of In2Se3 nanoflakes maintained at high temperature and open up the opportunities of 2D materials for novel applications in high-temperature nanoelectronic devices.展开更多
基金the grant from Research Grants Council of Hong Kong(GRF No.PolyU 153033/17P).
文摘Two-dimensional(2D)ferroelectric materials with unique structure and extraordinary optoelectrical properties have attracted intensive research in the field of nanoelectronic and optoelectronic devices,such as optical sensors,transistors,photovoltaics and non-volatile memory devices.However,the transition temperature of the reported ferroelectrics in 2D limit is generally low or slightly above room temperature,hampering their applications in high-temperature electronic devices.Here,we report the robust high-temperature ferroelectricity in 2D a-In2Se3,grown by chemical vapor depostion(CVD),exhibiting an out-of-plane spontaneous polarization reaching above 200℃.The polarization switching and ferroelectric domains are observed in In2Se;nanoflakes in a wide temperature range.The coercive field of the CVD grown ferroelectric layers ilustrates a room-temperature thickness dependency and increases drastically when the film thickness decreases;whereas there is no large variance in the coercive field at dfterent termperature from the samples with identical thickness.The results show the stable ferroelectricit of In2Se3 nanoflakes maintained at high temperature and open up the opportunities of 2D materials for novel applications in high-temperature nanoelectronic devices.
