Paper on LSZTO / Ge Electronic Structure Published in Phys Rev Mater

Our team’s latest paper on electronic structure mapping of LSZTO / Ge interfaces has just been published in Physical Review Materials! Led by Scott Chambers, this paper explores a detailed approach to the study of built-in potentials in buried interfaces and the role of unintended dopant defects.

From the abstract:

The electronic structures of semiconducting heterojunctions are critically dependent on composition including the presence and concentrations of dopants, both intended and unintended. Dopant profiles in the interfacial region can have major effects on band energies which in turn drive transport properties. Here we use core-level photoelectron line shapes excited with hard x-rays to extract information about electric fields resulting from internal charge transfer in epitaxial La0.03Sr0.97ZrxTi1−xO3/Ge(001) (0.1x0.7) heterostructures. Experiments were carried out for heterojunctions involving both n- and p-type Ge substrates. These heterojunctions were not amenable to electronic characterization of all regions by transport measurements because the doped substrates act as electrical shunts, precluding probing the more resistive films and masking interface conductivity. However, the core-level line shapes were found to be a rich source of information on built-in potentials that exist throughout the heterostructure and yielded valuable insight into the impact of band bending on band alignment at the buried interfaces. The electronic effects expected for Ge with uniform n- and p-type doping are eclipsed by those of unintended oxygen dopants in the Ge near the interface. This study illustrates the power of hard x-ray photoemission spectroscopy and related modeling to determine electronic structure in material systems for which insight from traditional transport measurements is limited.

To view the manuscript, visit: http://doi.org/10.1103/PhysRevMaterials.6.015002

To download the article directly, click here.