Tale of Two Bismuth Alkylthiolate Precursors’ Bifurcating Paths in Chemical Vapor Deposition

Abstract

We report on the application of two bismuth alkylthiolates, Bi(SR) 3 , differing only with respect to the alkyl substituents (R = −Bu t (1a); −Pr i (1b)) in the chemical vapor deposition (CVD) process as single-source precursors for both Bi 2 S 3 and Bi. Despite similar structural chemistry and chemical composition, the minor differences in the polarity of the bonds in Bi−S−C units in (1a) and (1b) resulted in strikingly different results in their lowtemperature (250 °C) decomposition. Whereas the CVD of Bi(SBu t ) 3 produced single-crystalline Bi 2 S 3 , elemental Bi was obtained from Bi(SPr i ) 3 . The CVD deposits in both cases were unambiguously identified as Bi 2 S 3 and Bi, as verified by X-ray diffraction (XRD) analysis, high-resolution X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The highly oriented and uniformly shaped two-dimensional (2D) Bi 2 S 3 platelets were found to be single crystalline by selected area electron diffraction (SAED) performed during high-resolution transmission electron microscopy (HRTEM) and correlative 2D-SEM−Raman spectroscopy. The photoconductivity of Bi 2 S 3 deposited on fluorine-doped tin oxide (FTO) was characterized by white light illumination that indicated the repetitive release of photoexcited charge carriers from deep-level defects.

Single-crystalline WSe2 nanoflakes as efficient electrocatalysts

“…Application of tailored molecular precursors offer potential for addressing the prevailing challenges of energy turnaround of materials processing methods, achieving high atom-economy for resource-efficient use of raw materials and reduction of consequent purification and post-synthesis treatment steps. [49][50][51][52][53] The approach reported here for the fabrication of high purity WSe 2 nanostructures by low-temperature transformation of a single molecular precursor emphasizes the power of synthesis in controlled growth of nanostructured materials. Leveraging the solubility in common organic solvents and stability of this precursor, microwaveassisted solvothermal decomposition enabled a rapid and reproducible material processing of crystalline WSe 2 flakes, as verified by chemical and structural analysis.…”

Synthesis and theoretical study of a mixed-ligand indium(iii) complex for fabrication of β-In2S3 thin films via chemical vapor deposition

“…The MOCVD tests were carried out in a cold-wall CVD reactor with cooling traps, an internal pressure sensor, and external temperature sensors at low-pressure settings, and the CVD chamber consisted of a quartz glass tube fitted with an inductively heated graphite holder on which the substrate (FTO) was mounted. 12 The deposited film, Pt coil and Hg/HgO are taken as the working (anode), counter (cathode) and reference electrodes. The molecular precursor was introduced to the reactor through a glass flange by applying dynamic vacuum (10 −3 mbar) and heating the precursor reservoir to the desired temperature.…”

“…9,10 Metal-ligand (M-S(Se)-R) interactions play a deterministic role in the formation of metal sulfides and selenides. 11,12 Gas-phase chemistry offers a unique opportunity to study the intrinsic reactivity of chemical species. 13 The metal-thiolate bonds can be strongly covalent, and involve different orbital interactions.…”

“…Quartz glass cuvettes with a length of 1 cm were employed for the purpose, and the spectra was subjected to baseline correction. The MOCVD tests were carried out in a cold-wall CVD reactor with cooling traps, an internal pressure sensor, and external temperature sensors at low-pressure settings, the CVD chamber consists of a quartz glass tube fitted with an inductively heated graphite holder on which substrate (FTO) was mounted12 . The deposited film, Pt coil and Hg/HgO are taken as a working (anode), counter (cathode) and reference electrode.…”