Scanning tunneling microscopy and spectroscopy of the semi-insulating CdZnTe(110) surface

The morphology and electronic structure of the (110) surface of semi-insulating CdZnTe has been studied by scanning tunneling microscopy and spectroscopy. The surface shows a 1 × 1 reconstruction whilst the tunneling spectra are highly rectified implying that imaging could only be performed at negative sample bias. Theoretical computations of the tunnel current have been used to fit to experiment to reveal the origin of each tunneling component and explain the rectification observed. The implications of various surface defects and surface states are considered. A discussion on scanning tunneling microscopy and spectroscopy on semi-insulating materials in general is also given.