Continuously tunable ferroelectric domain width down to the single-atomic limit in bismuth tellurite

Abstract

Emerging functionalities in two-dimensional materials, such as ferromagnetism, superconductivity and ferroelectricity, open new avenues for promising nanoelectronic applications. Here, we report the discovery of intrinsic in-plane room-temperature ferroelectricity in two-dimensional Bi2TeO5 grown by chemical vapor deposition, where spontaneous polarization originates from Bi column displacements. We found an intercalated buffer layer consist of mixed Bi/Te column as 180° domain wall which enables facile polarized domain engineering, including continuously tunable domain width by pinning different concentration of buffer layers, and even ferroelectric-antiferroelectric phase transition when the polarization unit is pinned down to single atomic column. More interestingly, the intercalated Bi/Te buffer layer can interconvert to polarized Bi columns which end up with series terraced domain walls and unusual fan-shaped ferroelectric domain. The buffer layer induced size and shape tunable ferroelectric domain in two-dimensional Bi2TeO5 offer insights into the manipulation of functionalities in van der Waals materials for future nanoelectronics.

Achieving Ferroelectricity in a Centrosymmetric High‐Performance Semiconductor by Strain Engineering

“…By contrast, strain tuning of phase transitions is of more fundamental interest, leading to profound property modification and phase engineering in 2D materials. 2D ferroelectricity (FE) has been observed in a number of ultrathin layered materials with either in-plane [5][6][7] or out-ofplane polarization, [8][9][10][11][12][13][14][15][16] such as monolayer SnTe, [5] CuInP 2 S 6 , [8,9] multilayer WTe 2 , [12] etc. The discovery of 2D FE has brought about a number of unprecedented physics, [17] including interfacial sliding FE [18,19] and switchable FE metal.…”

Ferroic Phases in Two-Dimensional Materials

“…107 Recently, robust in-plane ferroelectricity at room temperature was demonstrated in 2D Bi 2 TeO 5 . 108 The striped domains are observed in B 2 TeO 5 single crystal in the lateral PFM image; additionally, HAADF−STEM reveals an additional intercalated buffer layer composed of a mixed Bi/Te column in the direction of polarization switching (Figure 10e,f). The domain width may be continuously tuned, ranging from tens of nanometers to 1 nm depending on the Bi/Te ratio, and ferroelectric−antiferroelectric phase transition can be achieved when the ferroelectric domain width is reduced to half a unit cell (∼1 nm, Figure 10g,h).…”

“…Further, through kinked intercalated buffer layers, serial terraced domain walls and one-of-a-kind fan-shaped domain can be generated (Figure 10i). 108 3.1.2.7. Perovskite Structure Ferroelectric Thin Films.…”

Chemical vapor deposition of uniform bilayer PtS2 flakes for electrocatalytic hydrogen evolution

“…Notably, chemical vapor deposition (CVD) has been proved to be a facile method for synthesizing 2D materials. [11][12][13][14][15][16] Recently, polycrystalline PtS 2 thin films have been successfully obtained by directly sulfurizing Pt metal in a CVD furnace. [17][18][19] However, the successful CVD growth of 2D single-crystal PtS 2 with uniform thickness and tunable domain shape has not been implemented.…”