Investigation of Phase Transition from Critical Nucleus to Bi₂Te₃ Nanoplate Based on Screw Dislocation‐Driven Spiral Growth by Solvothermal Synthesis

Abstract

Two-dimensional bismuth telluride (Bi 2 Te 3 ) nanoplates have great potential for thermoelectrics and topological insulators. The material performance increases as the nanoplate size decreases. However, the initial stage of the crystal growth of the nanoplates has not been significantly investigated. The Bi 2 Te 3 nanoplates are prepared by solvothermal synthesis and the phase transition based on the screw dislocation-driven spiral growth of the nanoplates is investigated. The optimal synthesis conditions are first determined by controlling the Te concentration in the precursor solution. The spiral-grown nanoplates are collected from the synthesized products. The diameter of the critical nucleus is calculated to be in the range of 5.0-7.2 nm from the step width in the spiral. Subsequently, the solvothermal synthesis is implemented by changing the synthesis time from 15 to 1200 min under the optimal conditions of the precursor solution. Crystals are not grown in the solution at 15 min. At 25 min, an intermediate phase of Bi 2 TeO 5 with an approximate grain size of 5.0 nm is formed, which corresponds to the calculated diameter of the critical nucleus. Another intermediate phase of Te is formed, and the Bi 2 Te 3 nanoplates with a lateral size of 300 nm grow slowly at the expense of Bi 2 TeO 5 and Te.

Surface Modification of Bi2Te3 Nanoplates Deposited with Tin, Palladium, and Tin/Palladium Using Electroless Deposition

“…The studied Bi 2 Te 3 nanoplates were fabricated via a solvothermal technique. The detailed fabrication procedure is described in previous studies [62][63][64]. In brief, Bi 2 Te 3 nanoplates were fabricated as follows: 0.4 g of polyvinylpyrrolidone (PVP) (99.9% purity, K30, Ms ~40,000, Fujifilm Wako Co., Osaka, Japan) was dissolved in 18 mL of C 2 H 6 O 2 (99.5% purity, Fujifilm Wako Co., Osaka, Japan).…”

Defect-Mediated Growth of Layered Lateral Bi2Te3–Sb2Te3–Bi2Te3 Heterostructures

“…Concerning the growth mechanism of these heterostructures, it is well documented that the preferential growth of Bi 2 Te 3 or Sb 2 Te 3 nanocrystals occurs through the screw-dislocation-driven mechanism. , Classical crystal growth theory suggests that a lower supersaturation facilitates this mechanism, wherein a screw dislocation creates step edges for the incorporation of adatoms without the need for extra energy to overcome the energy barriers . Typically, a dislocation encompasses a dislocation core, containing displacements of atoms from perfect lattice positions .…”

Interfacial‐Modulated Growth of Nanostructured Bi2Te3 Films for Enhancing Thermoelectric Performance

“…Bi 2 Te 3 -based nanoplates with high boundary density can be solution synthesized to enhance the scattering of phonons and thus reduce κ. [17,18] Further adjustments to the arrangement, [19,20] heterostructures, [21,22] and pores [23,24] of the nanoplates can optimize their TE performance. However, transforming colloidal nanoplates into high-performance devices remains a challenge because films prepared by DOI: 10.1002/pssa.202200108 Little room remains for further reducing lattice thermal conductivity (κ L ) which cannot be reduced below the amorphous limit.…”