Low-temperature metalorganic vapor phase epitaxial growth of ZnS using diethyldisulphide as a sulphur precursor

The atmospheric pressure metalorganic vapor phase epitaxy (MOVPE) growth of ZnS using diethyldisulphide (Et2S2) as a sulphur precursor in combination with dimethylzinc:triethylammine adduct is reported. Et2S2 is used to achieve low-temperature (<400°C) growth of ZnS by pyrolytic MOVPE. The substitution of diethylsulphide (Et2S) with Et2S2 lowers the temperature of the process by almost 150°C, leading to growth rates in excess of 0.5 µm/h at around 400°C. The growth study is supplemented by the H-1 and C-13 nuclear magnetic resonance analysis of the Et2S2 batch used and by the results of mass spectrometry. The latter measurements allowed us to study the fragmentation path of the Et2S2+ ion. The about 150°C reduction of the ZnS growth temperature is explained as being due to the weaker S-C bonds occurring in the Et2S2 molecule with respect to those of Et2S; this is ascribed to the occurrence of the stronger S-S bond, which destabilizes the S-C bonds.