Purification of epitaxial InAs grown by liquid phase epitaxy using gadolinium gettering

Very pure InAs epitaxial layers of high quantum efficiency have been grown by liquid phase epitaxy using Gd gettering of the growth solution. The residual carrier concentration was reduced to ∼6×1015 cm−3 and the peak photoluminescence intensity increased considerably (between 10 and 100 times) using this technique. The low-temperature (4 K) photoluminescence spectra exhibited sharp bound exciton and donor-acceptor lines. The linewidth of the exciton was measured to be only 3.8 meV which is narrower than for undoped epitaxial InAs grown by other techniques.