One-step growth of thin film SnS with large grains using MOCVD

Abstract

Thin film tin sulphide (SnS) films were produced with grain sizes greater than 1 μm using a one-step metal organic chemical vapour deposition process. Tin–doped indium oxide (ITO) was used as the substrate, having a similar work function to molybdenum typically used as the back contact, but with potential use of its transparency for bifacial illumination. Tetraethyltin and ditertiarybutylsulphide were used as precursors with process temperatures 430–470 °C to promote film growth with large grains. The film stoichiometry was controlled by varying the precursor partial pressure ratios and characterised with energy dispersive X-ray spectroscopy to optimise the SnS composition. X-ray diffraction and Raman spectroscopy were used to determine the phases that were present in the film and revealed that small amounts of ottemannite Sn2S3 was present when SnS was deposited on to the ITO using optimised growth parameters. Interaction at the SnS/ITO interface to form Sn2S3 was deduced to have resulted for all growth conditions.

Effect of stacking sequence on the structural ordering and phase formation in the sequentially deposited copper zinc tin sulfide thin films

“…In Figure 3A, all the samples except sample S2‐520 exhibit the CZTS phase. The variation in the observed spectra of S2‐520 may be due to the presence of SnS (152 and 230 cm −1 ) and Sn 2 S 3 (304 cm −1 ) in the large proportion across the sample surface 41‐43 . Though there is a visible SnS secondary phase in S2 and S3 series from XRD patterns, there are no visible clues from Raman analysis.…”

“…The variation in the observed spectra of S2-520 may be due to the presence of SnS (152 and 230 cm À1 ) and Sn 2 S 3 (304 cm À1 ) in the large proportion across the sample surface. [41][42][43] Though there is a visible SnS secondary phase in S2 and S3 series from XRD patterns, there are no visible clues from Raman analysis. Further, some reports suggest the peak at 160 cm À1 to be of the SnS phase, 44 but the same peak is observed in the S1 series, which is entirely devoid of the SnS phase as seen from the corresponding XRD patterns rules out the peak to be of SnS phase.…”

A critical role of hydrogen sulfide evolution during MOCVD of single phase thin film tin sulfide using ditertiarybutylsulfide as a less toxic precursor

“…It was necessary to use a 6-fold greater concentration of t-Bu 2 S to Et 4 Sn due to the higher vapor pressure of sulfur compensating for its re-evaporation from the growing SnS film. The authors have reported [7] these optimised parameters in another article.…”

“…Unfortunately, H 2 S is a highly toxic gas so special measures are required for its use [6]. Ditertiarybutylsulfide (t-Bu 2 S) is an alternative sulfur source, with less toxicity than H 2 S and has been used by the authors employing the metal organic chemical vapor deposition (MOCVD) process [7]. Tetraethyltin (Et 4 Sn) was used in this study as the tin precursor with successful growth of single phase SnS on to molybdenum (Mo) substrates.…”

A combined experimental and modelling approach for the evaluation of the thermoelectric properties of Ag-doped SnS

“…SnS is attractive because it is low-cost, non-toxic and earth-abundant. 5 SnS crystalizes in a layered orthorhombic Pnma (or equivalent Pbnm and Pmcn) structure at room temperature and undergoes a reversible transformation to a more symmetric orthorhombic Cmcm phase at around 878 K. 6,7 The high-temperature phase has been associated with strongly-anharmonic lattice dynamics and a low, intrinsic lattice thermal conductivity. 8,9 However, while SnS possesses a high Seebeck coefficient, the electrical conductivity of pure SnS is very low due to its low intrinsic carrier concentration, resulting in a low power factor.…”