In situ laser reflectivity to monitor and control the nucleation and growth of atomically-thin 2D materials

Alexander A. Puretzk, Yu-Chuan Lin, Chenze Liu, Alex M Strasser, Yiling Yu, Stela Canulescu, Christopher M Rouleau, Kai Xiao, Gerd Duscher, David B. Geohegan

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The growth of atomically-thin two-dimensional (2D) layered and other quantum materials is typically performed without in situ monitoring or control. Here, a simple laser reflectivity approach is demonstrated to provide in situ control over sub-monolayer thickness and growth kinetics during pulsed laser deposition (PLD) of MoSe2 layers. First, the general technique is presented with emphasis on designing the maximum sensitivity of the optical contrast through consideration of Fresnel's equations with proper choice of layer thickness, substrate, and laser monitoring wavelength, incidence angle, and laser polarization. Then the 633 nm optical reflectivity of MoSe2 layers on SiO2/Si substrates was predicted and compared with in situ monitoring of MoSe2 growth by PLD under actual growth conditions using a probe HeNe laser beam. The measurements showed high sensitivity and excellent agreement with MoSe2 surface coverages calculated from atomic resolution STEM analysis of 2D layers deposited in arrested growth experiments. Growth kinetics revealed by these measurements showed sigmoidal nucleation and growth stages in the formation of the 2D MoSe2 layers that are described by a simple model, indicating the promise of the laser reflectivity technique for in situ monitoring and control of 2D materials deposition.

Original languageEnglish
Article number025048
Journal2D materials
Volume7
Issue number2
Number of pages11
ISSN2053-1583
DOIs
Publication statusPublished - 2020

Keywords

  • in situ reflectivity
  • Pulsed laser deposition (PLD)
  • 2D materials
  • MoSe2
  • kinetic modeling

Fingerprint Dive into the research topics of 'In situ laser reflectivity to monitor and control the nucleation and growth of atomically-thin 2D materials'. Together they form a unique fingerprint.

Cite this