Title: Anomalous Surface Doping Effect in Semiconductor Nanowires

Abstract

Surface doping is being used as an effective approach to improve the mechanical, optical, electronic, and magnetic properties of various materials. For example, experimental studies have proven that rare-earth element doping can enhance the optical properties of silicon nanostructures. However, the majority of previous investigations focused on either bulk materials or nanosized spherical crystals. Here we present a comparative study on semiconducting germanium (Ge) nanowires with and without surface doping by using multiple integrated characterization probes, including high resolution scanning/transmission electron microscopy (SEM/TEM), in situ high pressure synchrotron X-ray diffraction (XRD), and Raman spectroscopy. Our results reveal that under pressure the stability of the Ge-I phase (diamond structure) in erbium (Er)-doped Ge nanowires is enhanced compared to undoped Ge nanowires. We also found an increased stability of the Ge-II phase (body centered tetragonal structure) in Er-doped Ge nanowires during decompression. Furthermore, the presence of Er doping elevates the transition kinetics by showing a smaller pressure span needed for a complete Ge-I to Ge-II phase transformation. In contrast, Er doping has a negligible impact on the mechanical properties of Ge nanowires under high pressure, exhibiting a very different mechanical behavior from other foreign element-doped nanostructures. This anomalous doping effect was explainedmore » based on surface modification and decoration. Furthermore, these findings are of both fundamental and applied significance, because they not only provide a thorough understanding of the distinct role of surface doping in nanoscale materials, but also yield insight with regard to a given material’s design for favorable properties in semiconductor nanostructures.« less

Authors:

Wang, Yuejian  ^[1];

• Search DOE PAGES for author "Wang, Yuejian"
• Search DOE PAGES for ORCID "0000-0001-6663-5912"

Yang, Wenge ^[2]; Zou, Guifu  ^[3];

• Search DOE PAGES for author "Zou, Guifu"
• Search DOE PAGES for ORCID "0000-0002-8342-7768"

Wu, Ji ^[4]; Coffer, Jeffery L. ^[5]; Sinogeikin, Stanislav V. ^[6]; Zhang, Jianzhong ^[7]

---

+ Show Author Affiliations

1. Oakland Univ., Rochester, MI (United States)
2. Center for High Pressure Science and Technology Advanced Research, Shanghai (China); Carnegie Inst. of Washington, Argonne, IL (United States)
3. Soochow Univ., Jiangsu (China)
4. Georgia Southern Univ., Statesboro, GA (United States)
5. Texas Christian Univ., Fort Worth, TX (United States)
6. Carnegie Inst. of Washington, Argonne, IL (United States)
7. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:

Mon May 01 00:00:00 EDT 2017

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF); Robert A. Welch

OSTI Identifier:

1368340

Grant/Contract Number:  

AC02-06CH11357; NA0001974; P-1212

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Physical Chemistry. C

Additional Journal Information:

Journal Volume: 121; Journal Issue: 21; Journal ID: ISSN 1932-7447

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

ENGLISH

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; nanowires; compression; physical and chemical processes; phase transitions; doping