Cu–In–Te and Ag–In–Te colloidal nanocrystals with tunable composition and size

Abstract

We synthesize stable colloids of Cu-In-Te and Ag-In-Te nanocrystals using an amide-promoted technique, which enables independent size and composition control, and report the dependence of structural and optical properties on composition and size. Comparison to the synthesis of other ternary I-III-VI nanocrystals gives insight into the reaction mechanism and the generalizability of the amide-promote approach.

Colloidal Phase-Change Materials: Synthesis of Monodisperse GeTe Nanoparticles and Quantification of Their Size-Dependent Crystallization

“…In accordance with previous reports, the amide concentration has to be higher than that of the initial iodide anions, enabling full conversion to the germanium-amide intermediate followed by its fast reaction with the chalcogen (tellurium) precursor. 24 , 25 Small amounts of LiN(SiMe 3 ) 2 result in slower nucleation on fewer nucleation centers, leaving sufficient amounts of starting precursors for direct reaction and yielding broadly dispersed large-size GeTe nanoparticles. Figure 1 c illustrates these findings, showing a series of TEM images of GeTe products, prepared with different amounts of LiN(SiMe 3 ) 2 and otherwise identical reaction conditions.…”

Synthesis of small Ag–Sb–Te nanocrystals with composition control

“…Tellurides are promising candidates for a broad range of applications, such as infrared detection 1 , photoluminescence 2 , photovoltaics 3 , phase change memory 4 , and thermoelectrics 5 . Taking the example of thermoelectrics, several tellurides exhibit high figures-of-merit, zT (e.g., Bi 2 Te 3 6 , PbTe 7 , GeTe 8 , and AgSbTe 2 9,10 ).…”

“…While many binary telluride nanocrystals have been successfully synthesized (i.e., CdTe 28 , HgTe 29 , GeTe 30 , etc. ), there is only a handful of reports of size-uniform multicomponent telluride nanocrystals 2,31 . In fact, synthesis of colloidally stable AgSbTe 2 nanocrystals has only been reported once 32 .…”

“…Here, we present an amide-promoted synthesis, which yields small Ag x Sb 1-x Te 1.5-x nanocrystals with tunable composition between Ag 0.3 Sb 0.7 Te 1.2 and Ag 0.6 Sb 0.4 Te 0.9 (i.e., x ranges from 0.3 to 0.6). The choice of synthetic approach is motivated by previous success in preparing various chalcogenide nanocrystals 2,34,35 . Due to improved nucleation rates, amidepromoted synthesis typically provides small size nanocrystals and quantitative reaction yields at short reaction times.…”

Improvement of thermoelectric performance of copper-deficient compounds Cu2.5+δIn4.5Te8 (δ = 0–0.15) due to a degenerate impurity band and ultralow lattice thermal conductivity

“…Cu-In-Te ternary chalcogenides, such as, CuInTe 2 , [10][11][12][13] Cu 2 -In 4 Te 7 , 14 Cu 3 In 5 Te 9 (ref. 15 and 16) and Cu 3 In 7 Te 12 , 17 present potential TE performance, and we have observed the highest ZT value of 1.24 in Ag-added CuInTe 2 .…”