In this study, Cu-Sn-S nanoinks were synthesized by combining chelating polyetheramine to Cu, Sn, S powders of various concentrations. X-ray diffraction patterns indicate that nanoinks synthesized at low concentrations are composed almost entirely of binary phases SnS and Cu 2 S. Synthesizing nanoinks at higher concentrations decreased the quantity of binary phase and led to the appearance of ternary phase Cu 4 SnS 4 . Following sulfurization, single phase Cu 2 SnS 3 (CTS) thin film was obtained from nanoinks of low concentration; however, impurities, such as Cu 2 S were detected in the thin film obtained from nanoinks of high concentration. This can be attributed to the fact that lower concentrations reduce the reactivity of all the elements. As a result, the SnS phase reacted more readily and more rapidly, resulting in the early formation of a stoichiometric CTS thin film during sulfurization. Under these reaction conditions, Cu 2 S and SnS transform into CTS and thereby prevent the formation of unwanted phases of Cu 2 S and Cu 4 SnS 4 . Raman spectra revealed that second phase Cu 2 S phase remained in the high-concentration samples, due to an increase in reactivity due to the participation of a greater proportion of the copper in the reaction. The surface microstructure of low-concentration samples display closely packed Cu 2 SnS 3 grains with a flat morphology and an atomic composition ratio of Cu:Sn:S = 34.69:15.90:49.41, which is close to stoichiometric. Hall measurement revealed that low-concentration sample has superior electrical properties; i.e., a hole concentration of 5.23 × 10 17 cm −3 , mobility of 14.2 cm 2 /V-s, and optical band-gap energy of 1.346 eV, which are suitable for thin-film solar cells.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films