In the SnSe2 sample, a rough texture is noted in Fig. ) inset, possibly a characteristic of the phase . This observation led to notice that the same aspect exists at particular regions in the Sn(S0,5Se0,5)2 sample, as shown in the Fig. Therefore, this texture might be associated with the introduction of selenium in the structure, since this feature is not present in SnS2 sample. Interestingly, regions with a needle-like morphology are observed in the SnSe2 sample diluted in isopropanol, as shown in Fig. ). From energy dispersive spectroscopy (EDS), the composition of these needles reveals the presence of residual raw selenium in the structure. This result is in accordance with the Raman spectra, where additional vibration modes, associated with selenium, were identified in the SnSe2 samples (see ref. for further details). By changing the dilution medium to water, the residual selenium remains in the system as spherical colloids, which are indicated by the yellow arrows in Fig. ). This feature is typical of amorphous selenium (a-Se), which can crystallize in the trigonal (t-Se) phase as needles when diluted in isopropanol .