At the few-atom-thick limit, transition-metal dichalcogenides (TMDs) exhibit strongly interconnected structural and optoelectronic properties. The possibility to tailor the latter by controlling the former is guaranteed to have a great impact on applied and fundamental research. As shown here, proton irradiation deeply affects the surface morphology of bulk TMD crystals. Protons penetrate the top layer, resulting in the TMD-catalyzed production and progressive accumulation of molecular hydrogen in the first interlayer region. This leads to the blistering of one-monolayer thick domes, which stud the crystal surface and locally turn the dark bulk material into an efficient light emitter [1]. The domes are stable (>2-year lifetime) and robust, and host strong, complex strain fields. Lithographic techniques allow to engineer the formation process so that the domes can be produced with well-ordered positions and sizes tunable from the nanometer to the micrometer scale, with important prospects for so far unattainable applications.
References