We report on the application of two bismuth alkylthiolates,Bi(SR)3,differing only with respect to the alkyl substituents(R =-Bu~t(la);-Pr~i(lb)) in the chemical vapor deposition(CVD) process as single-source precursors for both Bi2S3 and Bi.Despite similar structural chemistry and chemical composition,the minor differences in the polarity of the bonds in Bi-S-C units in(la) and(lb) resulted in strikingly different results in their low-temperature(250 ℃) decomposition.Whereas the CVD of Bi(SBu~t)3 produced single-crystalline Bi2S3,elemental Bi was obtained from Bi(SPr~t)3.The CVD deposits in both cases were unambiguously identified as Bi2S3 and Bi,as verified by X-ray diffraction(XRD) analysis,high-resolution X-ray photoelectron spectrosco-py(XPS),and scanning electron microscopy(SEM).The highly oriented and uniformly shaped two-dimensional(2D) Bi2S3 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 Bi2S3 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.
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