Ultrathin 2D Nonlayered Tellurium Nanosheets: Facile Liquid‐Phase Exfoliation, Characterization, and Photoresponse with High Performance and Enhanced Stability

Abstract

Nonlayered materials are constructed with chemical covalent bonds in all three dimensions, distinct from layered materials, which contain evident structural differences in the horizontal and vertical directions. As a consequence, liquid‐phase exfoliation (LPE), a widely explored technique to obtain 2D layered nanoarchitectures, has not yet been fully characterized for the realization of 2D nonlayered nanostructures. Herein, by virtue of a typical chain‐like structure of crystalline bulk Te with strong TeTe covalent bonds in intrachains and weak Van der Waals forces in interchains, ultrathin 2D nonlayered Te nanosheets are realized by means of an LPE method. The resultant 2D Te nanosheets possess a broad lateral dimension ranging from 41.5 to 177.5 nm and a thickness ranging from 5.1 to 6.4 nm, and its photoresponse properties are evaluated using photoelectrochemical measurements. The 2D Te nanosheets exhibit excellent photoresponse behaviors from the UV to the visible regime in association with strong time and cycle stability for the on/off switching behaviors. The fabrication approach of 2D Te nanosheets would arouse interest in exfoliating other nonlayered 2D materials, which would expand the family of 2D materials.

Ternary Pb 1− x Cd x S quantum dot-based UV-vis-NIR photoelectrochemical photodetection with superior photoresponsivity and detectivity

“…2c. The Pb 0.50 Cd 0.50 S QD-based PEC electrode displays the best PEC performance in an alkaline electrolyte, in good accordance with the previously reported Xene-based PEC electrodes, such as tellurene 27 and bismuthene-based PEC electrodes. 25 The PEC signal for the Pb 0.50 Cd 0.50 S QD-based PEC electrode gradually increases with the KOH concentration (0.001–0.1 M) at 0.4 V, mainly attributed to the decreased interfacial resistance ( R = 327, 84 and 17 Ω in 0.001, 0.01, and 0.1 M KOH, respectively, Fig.…”

Epitaxial Growth of Topological Insulators on Semiconductors (Bi2Se3/Te@Se) toward High‐Performance Photodetectors

“…The corresponding bandgap ( E g ) energies of the pristine Te NTs, Te@Se NTs, and Bi 2 Se 3 /Te@Se were calculated according to the Tauc plots (the inset image in Figure a). The Te NTs shows E g of 1.83 eV, consistent with the previous report . It should be noted that the E g decreases to 1.09 eV after Se growth, and further decreases to 0.86 eV after epitaxial growth of Bi 2 Se 3 NSs on the surface of Te@Se NTs, both of which are significantly lower than that of Te NTs.…”

Enhanced Photodetection Properties of Tellurium@Selenium Roll‐to‐Roll Nanotube Heterojunctions

“…The secondary electron cutoff region can be derived by a linear extrapolation of the edge (insert in Figure B). The E g of 1.0 eV for Te nanotubes is close to that of ultrathin Te nanosheets reported by Zhang and co‐workers . Moreover, with a Se layer on the Te nanotubes, E g of Te x @Se y increases to 1.5 eV for Te 0.44 @Se 0.56 and 1.8 eV for Te 0.37 @Se 0.63 , attributed to the relatively higher E g of Se compared to that of Te .…”