Optical and structural properties of ZnS grown by atomic layer epitaxy

Monocrystalline films of sphalerite-type ZnS are produced on (001) GaAs substrates by atomic layer epitaxy (ALE) in a gas flow system employing reactions of three different types. Properties of these ZnS films are compared. The best quality ZnS layers are obtained using either zinc chloride or elemental zinc as source of cation and H2S vapors as source of sulfur. These layers show flat surfaces and good spectral properties.