Revealing atomically sharp interfaces of two-dimensional lateral heterostructures by second harmonic generation

Author(s)

Sousa, Frederico B. ^[1] ; Lafeta, Lucas ^[1] ; Cadore, Alisson R. ^[2] ; Sahoo, Prasana K. ^[3] ; Malard, Leandro M. ^[1]

Affiliation

^[1] Univ Fed Minas Gerais, Dept Fis, BR-30123970 Belo Horizonte, MG - Brazil

^[2] Univ Prebiteriana Mackenzie, MackGraphe Graphene & Nanomat Res Ctr, BR-01302907 Sao Paulo - Brazil

^[3] Indian Inst Technol Kharagpur, Mat Sci Ctr, Kharagpur 721302, W Bengal - India

• Document type: Journal article
• Source: 2D MATERIALS; v. 8, n. 3 JUL 2021.
• Web of Science Citations: 0

Abstract

The interface between two different semiconductors is crucial in determining the electronic properties at the heterojunction, therefore novel techniques that can probe these regions are of particular interest. Recently it has been shown that heterojunctions of two-dimensional transition metal dichalcogenides have sharp and epitaxial interfaces that can be used to the next generation of flexible and on chip optoelectronic devices. Here, we show that second harmonic generation (SHG) can be used as an optical tool to reveal these atomically sharp interfaces in different lateral heterostructures. We observed an enhancement of the SH intensity at the heterojunctions, and showed that is due to a coherent superposition of the SH emission from each material. This constructive interference pattern reveals a phase difference arising from the distinct second-order susceptibilities of both materials at the interface. Our results demonstrate that SHG microscopy is a sensitive characterization technique to unveil nanometric features in layered materials and their heterostructures. (AU)

• FAPESP's process: 20/04374-6 - Fabrication and characterization of mid-infrared waveguides with graphene nanoribbon arrays
• Grantee: Alisson Ronieri Cadore
• Support Opportunities: Scholarships in Brazil - Post-Doctoral