Title: Vapor-Phase Intercalation of Cesium into Black Phosphorous

Abstract

Cesium vapors were charged into black phosphorous (BP) flakes at varied times and at a temperature gradient of 150 °C. The X-ray diffraction (XRD) measurements of these samples suggest a reduction in the strength of van der Waal interactions between BP layers leading to the loss of coherence of out-of-plane peaks. At the same time, the three main Raman modes of BP (A_g¹, B_2g, and A_g²) steadily redshifted as exposure times were increased, with modes B_2g and A_g² shifting faster than A_g¹. After initial rapid downshifts of active BP phonon modes, this intercalation strategy showed its limits following prolonged exposure times. Saturation of BP flakes by Cs vapors ensued and the kinetics was fitted with an exponential decay function. Furthermore, the thermoelectric power (TEP) of cesiated BP exhibited an inversion in sign from positive to negative around 400 K, lending credence to the transformation of as-prepared BP which is a p-type semiconductor to an n-type equivalent due to Cs atom intercalation driven shifting of the Fermi level toward the conduction band of BP and the donation of electrons from Cs. Furthermore, density functional theory (DFT) calculations were used to delve deeper into understanding Cs intercalation on the structural evolution ofmore » BP.« less

Authors:

Abu, Usman O. ^[1]; Musa, Md Rajib Khan ^[1]; Rajapakse, Manthila ^[1]; Karki, Bhupendra  ^[1];

• Search DOE PAGES for author "Karki, Bhupendra"
• Search DOE PAGES for ORCID "0000-0002-9942-2056"
• Search orcid.org for ORCID "0000-0002-9942-2056"

Vithanage, Dinushika ^[1]; Yu, Ming ^[1]; Sumanasekera, Gamini ^[1]; Jasinski, Jacek B.  ^[1]

• Search DOE PAGES for author "Jasinski, Jacek B."
• Search DOE PAGES for ORCID "0000-0002-1297-6145"
• Search orcid.org for ORCID "0000-0002-1297-6145"

---

+ Show Author Affiliations

1. Univ. of Louisville, KY (United States)

Publication Date:

2021-12-01

Research Org.:

Univ. of Louisville, KY (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1834141

Grant/Contract Number:  

SC0019348

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Physical Chemistry. C

Additional Journal Information:

Journal Volume: 125; Journal Issue: 49; Journal ID: ISSN 1932-7447

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

77 NANOSCIENCE AND NANOTECHNOLOGY; 36 MATERIALS SCIENCE; Layers; Two dimensional materials; Diffraction; Cesium; Intercalation