Fabrication of silicon-based flexible optical waveguide by edge-cutting transfer technique

Abstract

Owing to remarkable advantages in flexible, portable, and large area characteristics, inorganic flexible electronics/ photonics have attracted widespread attentions and got full progresses. The key technique for fabrication of inorganic flexible electrical/optical devices is transferring nano-building blocks from conventional rigid substrates to flexible substrates in a manner of controllable, accurate, and ultrahigh alignment. This paper focused on the well-regulated transfer and deterministic assembly of these nano-building blocks onto flexible substrate during transfer printing process, and proposed edge-cutting transfer technique to fabricate and deterministically assemble silicon nanoribbon arrays on flexible substrate. Based on the beam theory and finite element model, the relationships between stress existing in suspended silicon nanoribbons and thickness and width of nanoribbons during edge-cutting transfer process are studied. Moreover, the edge morphologies of the fabricated nanoribbons are investigated with different directions of the initially defined silicon strips. And the silicon nanoribbons with sharp edges can be obtained by optimizing the defined directions of the silicon strips. Ultimately, silicon-based flexible optical waveguide was demonstrated by using the obtained silicon nanoribbon.