Direct Characterization of Band Bending in GaP/Si(001) Heterostructures with Hard X-ray Photoelectron Spectroscopy

TL;DR

This study uses hard X-ray photoelectron spectroscopy to directly measure and analyze the band bending in GaP/Si heterostructures, providing a new method for characterizing buried semiconductor interfaces.

Contribution

It demonstrates the effectiveness of HAXPES with variable photon energy for depth-resolved electronic structure analysis of heterointerfaces.

Findings

Depth profiles of binding energies match previous phonon spectroscopy results.

HAXPES effectively characterizes electric potential profiles at buried interfaces.

Method provides quantitative insights into band bending in heterostructures.

Abstract

We apply hard X-ray photoelectron spectroscopy (HAXPES) to investigate the electronic structures in ~50-nm thick epitaxial GaP layers grown on Si(001) under different conditions. Depth profiles of the local binding energies for the core levels are obtained by measuring the photoemission spectra at different incident photon energies between 3 and 7 keV and analyzing them with simple numerical models. The obtained depth profiles are in quantitative agreement with the band bending determinations for the same samples in a previous coherent phonon spectroscopic study. Our results demonstrate the applicability of the HAXPES with varying incident photon energy to characterize the electric potential profiles at buried semiconductor heterointerfaces.