Synthesis of Hexagonal Sb₂Te₃ Nanoplates by Thermal Decomposition of the Single-Source Precursor (Et₂Sb)₂Te.

Abstract

The size-selective synthesis of hexagonal Sb2Te3 nanoplates by thermal decomposition of the single source precursor bis(diethylstibino)telluride (Et2Sb)2Te is described for the first time. The role of the thermolysis temperature and the concentration of the capping agent (PVP*) on the growth of the nanoplates was investigated. The thermal properties of (Et2Sb)2Te were investigated by differential scanning calorimetry (DSC) and the resulting Sb2Te3 nanoplates were characterized by XRD, SEM, TEM, EDX and SAED. Moreover, electrical conductivity and Seebeck coefficient and thermal conductivity of the nanoplates were determined, clearly proving the enhanced thermoelectric properties of nanosized antimony telluride.

Covalently bonded compounds of heavy group 15/16 elements – Synthesis, structure and potential application in material sciences

“…[168] In contrast, the decomposition pathways of (Et 2 Sb) 2 E (E = S, Se) are more complex. As was previously observed, [7] (Et 2 Sb) 2 S decompose with formation of SbR 3 und Sb 2 S 3 .…”

“…SEM photographs of Sb 2 S 3 nanobundles (a), Sb 2 Se 3 nanowires (b) and Sb 2 Te 3 nanoplates (c) synthesized with (Et 2 Sb) 2 E (E = S, Se, Te) at 170 °C. [168,169] According to TEM studies, the crystalline Sb 2 S 3 nanobundles and Sb 2 Te 3 nanowires are as long as 5 µm and show diameters below 150 nm in the middle (Fig. 29).…”

“…170 °C. [168,169] Cold pressed pellets of the Sb 2 Te 3 nanoplates with densities of 5.6 g/cm 3 and 5.75 g/cm 3 , corresponding to 85 % and 87 % of the bulk density of Sb 2 Te 3 (6.57 g/cm 3 ), showed high Seebeck coefficients  between 145 μV/K and 170 μV/K. These values are close to optimized values of bulk materials, [176] hence demonstrating a low defect density and low carrier axis.…”

“…annealing (black open squares), and a powder exposed to a rapid thermal annealing (RTA; red filled squares) are shown. [168] According to these results, further improvement of the thermoelectric properties of the material was required. While the use of a single source precursor allowed the careful control of the charge carrier concentration by providing Sb and Te in the correct stoichiometric ratio (Sb 2 Te 3 ), the second major aspect on optimizing the given thermoelectric material is by M a n u s c r i p t 47 careful control of the carrier mobility.…”

“…Since pure Et 3 Sb starts to decompose at about 240 °C, [168] the substrate temperature should not exceed 220 °C. EDX studies also revealed the presence of small amounts of carbon (5-6%), which are rather located on the substrate surface due to incompletely decomposed precursor residues as was shown by scanning Auger electron microscopy studies (SAM/AES).…”