Strain engineering has quickly emerged as a viable option to modify the electronic, optical, and magnetic properties of 2D materials. However, it remains challenging to arbitrarily control the strain. Here we show that, by creating atomically flat surface nanostructures in hexagonal boron nitride, we achieve an arbitrary on-chip control of both the strain distribution and magnitude on high-quality molybdenum disulfide. The phonon and exciton emissions are shown to vary in accordance with our strain field designs, enabling us to write and draw any photoluminescence color image in a single chip. Moreover, our strain engineering offers a powerful means to significantly and controllably alter the strengths and energies of interlayer excitons at room temperature. This method can be easily extended to other material systems and offers promise for functional excitonic devices.
Keywords: 2D materials; atomic-scale etching; hexagonal boron nitride; interlayer exciton; strain engineering; transition metal dichalcogenide.