Resonant optical phase imaging of lateral transition metal dichalcogenides heterostructure junctions with sub-micron width as high-throughput inspection

Abstract

Lateral MoS<inf>2</inf>–WS<inf>2</inf> heterostructures are essential for scalable in-plane optoelectronic junctions, yet their interfaces often show weak optical contrast that obscures their identification in bright-field microscopy. Raman and Photoluminescence (PL) mapping clearly resolves the junction through excitonic contrast, but its raster-scanning nature limits rapid, large-area inspection. Here, we show that hyperspectral phase microscopy (HPM) imaging provides a fast, wide-field indicator of weak contrast MoS<inf>2</inf>–WS<inf>2</inf> junctions. Direct comparison of PL and HPM acquired from the same regions reveals that the HPM phase shift retains a consistent spatial contrast across the heterointerface, enabling reliable interface localization comparable to PL. Line-profile and correlation analyses confirm that HPM captures the junction position with high reproducibility. These results establish phase-based imaging as a practical complement to PL for rapid visualization and process-level monitoring of lateral transition-metal dichalcogenides (TMDs) heterostructures. © 2026