Title: Cathodoluminescence of Ultrathin Twisted Ge_1–xSn_xS van der Waals Nanoribbon Waveguides

Abstract

Abstract Ultrathin van der Waals semiconductors have shown extraordinary optoelectronic and photonic properties. Propagating photonic modes make layered crystal waveguides attractive for photonic circuitry and for studying hybrid light–matter states. Accessing guided modes by conventional optics is challenging due to the limited spatial resolution and poor out‐of‐plane far‐field coupling. Scanning near‐field optical microscopy can overcome these issues and can characterize waveguide modes down to a resolution of tens of nanometers, albeit for planar samples or nanostructures with moderate height variations. Electron microscopy provides atomic‐scale localization also for more complex geometries, and recent advances have extended the accessible excitations from interband transitions to phonons. Here, bottom‐up synthesized layered semiconductor (Ge _{1– x} Sn _x S) nanoribbons with an axial twist and deep subwavelength thickness are demonstrated as a platform for realizing waveguide modes, and cathodoluminescence spectroscopy is introduced as a tool to characterize them. Combined experiments and simulations show the excitation of guided modes by the electron beam and their efficient detection via photons emitted in the ribbon plane, which enables the measurement of key properties such as the evanescent field into the vacuum cladding with nanometer resolution. The results identify van der Waals waveguides operating in the infrared and highlightmore » an electron‐microscopy‐based approach for probing complex‐shaped nanophotonic structures.« less

Authors:

Sutter, Peter  ^[1];

• Search DOE PAGES for author "Sutter, Peter"
• Search DOE PAGES for ORCID "0000-0002-3301-309X"

Khorashad, Larousse Khosravi ^[1]; Argyropoulos, Christos ^[1]; Sutter, Eli ^[1]

---

+ Show Author Affiliations

1. Univ. of Nebraska, Lincoln, NE (United States)

Publication Date:

Sun Dec 06 00:00:00 EST 2020

Research Org.:

Univ. of Nebraska, Lincoln, NE (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); US Department of the Navy, Office of Naval Research (ONR)

OSTI Identifier:

1780782

Alternate Identifier(s):

OSTI ID: 1804198

Grant/Contract Number:  

SC0016343; N00014-19-1-2384

Resource Type:

Accepted Manuscript

Journal Name:

Advanced Materials

Additional Journal Information:

Journal Volume: 33; Journal Issue: 3; Journal ID: ISSN 0935-9648

Publisher:

Wiley

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; Layered Materials; Nanoribbons; Alloys; Excitons; Nanophotonics