Growth of Zn3As2 on GaAs by liquid phase epitaxy and their characterization

Zn3As2 epitaxial layers were grown on GaAs (1 0 0) substrates by liquid phase epitaxy (LPE) using Ga as the solvent. Zinc mole fraction in the growth melt was varied from 1.07×10−2 to 6×10−2. X-ray diffraction spectrum exhibits a sharp peak at 43.3° characteristic of Zn3As2 crystalline layer. The peak intensity increases with increase in zinc mole fraction in the growth melt. The compositions of the as-grown Zn3As2 layers were confirmed by energy dispersive X-ray (EDX) analysis. Surface morphology was studied using scanning electron microscopy (SEM) and the thickness of the epilayers was also determined. The Hall measurements at 300 K indicate that Zn3As2 epilayers are unintentionally p-doped. With an increase of zinc mole fraction in the growth melt, carrier concentration increases and carrier mobility decreases. Infrared optical absorption spectroscopy showed a sharp absorption edge at 1.0 eV corresponding to the reported band gap of Zn3As2.