Experimental evidence of the two-dimensional electron gas in CdS quantum wells of CdS/ZnSe heterostructures

We report to our knowledge the first experimental observation of a two-dimensional electron gas (2DEG) in CdS quantum wells of CdS/ZnSe quantum heterostructures grown by molecular beam epitaxy (MBE). The CdS layers were about 4 nm thick, and the thicknesses of the doped ZnSe layers and of the growth temperatures of the structures were varied in order to investigate their influence on the 2DEG parameters. The effective sheet concentration of 2DEG reached up to 1.5x10(13) cm(-2). The maximal Hall mobility was nevertheless less than or equal to 380 cm(2)/Vs. Possible scattering mechanisms that cause such values are discussed. Most probably it is scattering by stacking faults or by interface roughness.