Tip-enhanced Photoluminescence of Freestanding Lateral Heterostructures

Two-dimensional (2D) materials have promising applications that are based on the tunability of their optical and electronic properties. We investigated the photoluminescence (PL) signals of freestanding lateral WSe₂-MoSe₂ heterostructures transferred from a Si/SiO₂ substrate onto a TEM copper grid under the influence of strain exerted by a scanning probe microscope (SPM) gold-coated plasmonic tip. We studied the nanobubbles formed in heterostructures by nanoindentation as a function of the tip-sample distance. We investigated the near-field tip-enhanced PL (TEPL) signals from both MoSe₂ and WSe₂ nanobubbles and their junction heterostructures. The observed tunability and nanoscale control open new possibilities to control the performance of optoelectronic nanodevices.