Growth and characterization of InAs layers obtained by liquid phase epitaxy from Bi solvents

摘要

In this paper, we report the first liquid phase epitaxial growth of InAs epitaxial layers using 100% Bi solvent. At a growth temperature of 470 ℃, the layers are macroscopically mirror like and the obtained growth rate is ～ 40 nm min~(-1). High-resolution XRD measurements reveal perfect lattice matching between the layer and the substrate, very good structural quality of the layers and less than 0.07% content of substitutional Bi in the layer. Raman spectra from background-doped layers are indicative of carrier concentration near the epilayer surface of less than 10~(16) cm~(-3), while assessment of these layers by means of infrared reflectance spectroscopy points to carrier concentration in the bulk of the layers of the order of 1 x 10~(15) cm~(-3). 4 K photoluminescence spectra from the same layers exhibit excitonic lines with half-widths ≤ 3 meV, which is a signature for electron concentration comparable to the known critical Mott density in InAs of ～ 5 x 10~(14) cm~(-3). We attribute the low background doping of the epitaxial layers to the low dissolution in Bi of Si and other residual impurities at 470 ℃.