Shape-controlled aerosol-assisted chemical vapour deposition of iron sulfide thin films using heterocyclic iron(II) dithiocarbamates as single-source molecular precursors
Year: 2025
Type: article
Abstract: Iron sulfide (FeS) thin films are promising materials for renewable energy technologies due to their low toxicity, cost-effectiveness, and tunable optoelectronic properties. However, achieving phase-pure FeS with controlled morphology remains challenging. In the present study, the fabrication of iron sulfide films via aerosol-assisted chemical vapor deposition (AACVD) of bis -(piperidinedithiocarbamato)iron(II) ( 1 ) and bis -(tetrahydroquinolinedithiocarbamato)iron(II) ( 2 ) complexes as single-source molecular precursors is reported. Unlike previous studies which predominantly focused on Fe(III)-based precursors, this work demonstrates the unexplored potential of Fe(II) precursors in tailoring phase purity, crystallinity, and morphology of the iron sulfide thin films. Thermogravimetric analysis confirmed clean precursor decomposition, yielding FeS residues. The deposition of iron sulfide films were carried at temperatures of 350 °C and 450 °C using chloroform solution of precursors, and the resulting films were characterized for structural, optical, and morphological properties. Films deposited using precursor ( 1 ) at 350 °C displayed uniform spherical particles ranging from 240 nm to 370 nm and a direct band gap of 2.29 eV while those at 450 °C revealed anisotropic growth (650 – 1050 nm) and a reduced band gap of 2.19 eV, attributed to quantum confinement effects. Besides, films obtained from precursor ( 2 ) produced the films in the range of 248 – 364 nm for 350 °C and larger sizes in the range of 1.1 – 1.6 µm for 450 °C deposition temperatures. X-ray diffraction confirmed hexagonal Fe₀.₉₇₅S phase formation, with improved crystallinity at higher temperatures. Atomic force microscopy revealed smoother surfaces for films derived from the piperidine-based precursor. These findings establish Fe(II) dithiocarbamates as promising precursors for controlled FeS thin film synthesis and provide a tunable route for tailoring optoelectronic properties for photovoltaic technologies.
Source: Next Materials
Author: Sixberth Mlowe
Institution: University of Dar es Salaam
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,280
Funder: University of Dar es Salaam
Award: G6524035979
OpenAlex ID: W4413435545