Electronic and Structural Analysis of TMD/BP Heterostructures: Insights from Raman Spectroscopy, SEM, and Correlative Probe Electron Microscopy

¹ Department of CSE, GRIET, Bachupally, Hyderabad, Telangana, India.
² Uttaranchal University, Dehradun - 248007, India
³ Centre of Research Impact and Outcome, Chitkara University, Rajpura - 140417, Punjab, India
⁴ Lovely Professional University, Phagwara, Punjab, India,
⁵ Chitkara Centre for Research and Development, Chitkara University, Himachal Pradesh - 174103 India
⁶ Department of Chemistry, Research & Incubation Centre, Rayat Bahra University, Chandigarh-Ropar NH 205, Greater Mohali, Punjab, 140103, India

^* Corresponding author: rndeepa.pradeep@gmail.com

Abstract

The current study was designed in order to study the electrical and structural properties of heterostructures of TMD and BP through Raman spectrum mapping technique, Scanning electron microscopy (SEM) and Correlative Probe electron microscopy (CPEM). Single and few layer heterostructures were prepared by mechanical exfoliation and transferred onto a silicon substrate by poly(methyl methacrylate) (PMMA) transfer method. Optical and CPD mapping manifested increased signal intensity at the edges of the flake, and Raman spectroscopy indicated definite electron density near the fringes of the flake. In this system, scanning electron microscopy (SEM) studies performed employing a range of accelerating voltages have supported the presence of electronic domains within the heterostructures especially at their borderlines. The CPEM analysis showed a significant correlation between the topographical and electronic contrast, where the former was attributed to an intense accumulation of electrons at the edge of the flake and not due to structural flaws. These results highlight the fact that TMD/BP heterostructures possess relatively unique electrical properties and may be suitable for future optoelectronic applications.