Interface formation and Schottky barrier height for Y, Nb, Au, and Pt on Ge as determined by hard x-ray photoelectron spectroscopy

Published

January 6, 2023

Author(s)

Abdul Rumaiz, Ian Harding, Conan Weiland, Neha Nooman, Thomas Krings, Ethan Hull, Gabriele Giacomini, Wei Chen, Eric J. Cockayne, D. Peter Simmons, Joseph Woicik

Abstract

Development of a robust, thin, hole-blocking (n+) contact on high purity germanium (HPGe) has been the main challenge in the development of Ge-based radiation sensors. Yttrium has been reported to be a viable hole-blocking contact on HPGe, and detectors with low leakage have been fabricated. Niobium has also been considered as a potential hole-blocking contact due to its low work function. Here we investigate interface chemistry and the Schottky barrier height of Y and Nb, as well as electron-blocking contacts Au and Pt, on Ge (100) surfaces using hard X-ray photoelectron spectroscopy. We find a barrier height of 1.05 eV ± 0.10 eV for Y/HPGe, confirming the formation of a hole-blocking barrier. For Nb/HPGe, the barrier height of 0.13 eV ± 0.10 eV demonstrates that the interface is not hole-blocking. The Au and Pt Schottky barrier were found to be 0.45 eV ± 0.10 eV and 0.51 eV ± 0.10 eV, respectively.

Citation

AIP Advances

Volume

13

Pub Type

Journals

Download Paper

https://doi.org/10.1063/5.0101688

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Keywords

Germanium, germanium-metal heterojunctions, Schottky barrier, hard x-ray photoelectron spectroscopy, density functional theory, electronic density of states

Citation

Rumaiz, A. , Harding, I. , Weiland, C. , Nooman, N. , Krings, T. , Hull, E. , Giacomini, G. , Chen, W. , Cockayne, E. , Simmons, D. and Woicik, J. (2023), Interface formation and Schottky barrier height for Y, Nb, Au, and Pt on Ge as determined by hard x-ray photoelectron spectroscopy, AIP Advances, [online], https://doi.org/10.1063/5.0101688, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=934779 (Accessed October 1, 2025)