Peculiar spectra and photocurrent oscillation caused by laser interference in WX 2 (X = S, Se) bubbles

摘要: We report the successful synthesis of WX2 (X = S, Se) crystals by chemical vapor deposition and fabrication micron-sized bubbles on via a facile annealing process in Ar atmosphere. The optical fluorescence images show evident interference oscillating rings spherical cap-shaped bubbles, such can cause intensity oscillations photoluminescence (PL) Raman mapping images, which are mainly attributed to local thermal effect. Structure this bubble profoundly affects band structure WX2, as appearance direct bandgap few-layer WSe2 bubbles. Similar monolayer WS2 bubble, deconvoluted PL peaks exhibit obvious oscillation normalized integral intensity, position width external pressure decreases. In addition, photocurrent bilayer devices unambiguously reveal phenomenon due enhancement or decrement suspended film. Our results open up novel avenue optoelectronics manipulating 2D material