Optoelectronic Thinning of Transition Metal Dichalcogenides for Device Fabrication

Abstract

Atomically thin transition metal dichalcogenides (TMDCs) are promising materials for nanodevices due to their extraordinary electronic, optoelectronic, and mechanical properties. However, massive production of high-quality atomic monolayers of TMDCs remains challenging. Herein, we report a self-limiting optoelectronic thinning method for fabrication of monolayers of TMDCs and their micro/nanopatterns at the large scale and in a versatile manner. By properly choosing the wavelength of our working laser beams, we selectively excited electrons between indirect band gap of bulk or few-layer Mos2,which promoted the thinning of the TMDCs via electrochemical degradation. Once the Mos2reached atomic monolayers, our laser beam could not excite the electrons over the wider direct band gap. Therefore, the electrochemical reaction stopped and the Mos2remained as atomic monolayers.