Electrical properties of modulation-doped HgTe–CdTe superlattices

Abstract

Growth of modulation-doped HgTe–CdTe superlattices (SLs) at very low temperatures (140 °C) by photoassisted molecular beam epitaxy is reported. SL layer thicknesses were intentionally chosen such that most of the SLs studied are inverted-band semimetals or inverted-band semiconductors. Both p- and n-type samples were successfully prepared and studied. The doped superlattices exhibit excellent electrical properties. Lack of carrier freeze-out at low temperatures provides convincing evidence that modulation-doping has been achieved.