Multidimensional Coherent Spectroscopy of van der Waals materials and heterostructures (Final Technical Report)

Technical Report · Mon Dec 22 00:00:00 EST 2025

DOI:https://doi.org/10.2172/3009800· OSTI ID:3009800

Cundiff, Steven T. ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States)

This project advanced multidimensional coherent spectroscopy (MDCS) and related spectroscopic-imaging methods as quantitative probes of many-body optical excitations in two-dimensional (2D) van der Waals (vdW) semiconductors and their heterostructures. Monolayer transition-metal dichalcogenides (TMDs) such as MoSe₂ and WSe₂ provide a uniquely strong platform for excitonic physics due to reduced dielectric screening, which enhances Coulomb interactions and makes higher-order correlated states (e.g., biexcitons and exciton–trion correlations) more prominent than in conventional bulk semiconductors. At the same time, the same sensitivity that enables strong interactions also increases susceptibility to spatial inhomogeneity—e.g., strain gradients, wrinkles, nanoscale disorder potentials, and charge puddling—which can broaden resonances, obscure interaction signatures, and complicate device-to-device reproducibility. The work reported here addressed this dual opportunity and challenge by: (i) developing and deploying coherent multidimensional methods (including double-quantum MDCS) capable of isolating interaction signals with reduced background, (ii) integrating electrostatic control to tune carrier populations and interaction strengths in situ, and (iii) introducing complementary spatially resolved photoluminescence (PL) techniques—hyperspectral PL imaging and polarization-/field-dependent PL lineshape analysis—to directly quantify disorder, strain, and localization that govern the coherent response.

• Research Organization: Univ. of Michigan, Ann Arbor, MI (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: SC0022179
• OSTI ID: 3009800
• Report Number(s): DOE-UMICH--22179
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE