Designing Inorganic Semiconductors with Cold‐Rolling Processability

Abstract

While metals can be readily processed and reshaped by cold rolling, most bulk inorganic semiconductors are brittle materials that tend to fracture when plastically deformed. Manufacturing thin sheets and foils of inorganic semiconductors is therefore a bottleneck problem, severely restricting their use in flexible electronics applications. It was recently reported that a few singlecrystalline two-dimensional van der Waals (vdW) semiconductors, such as InSe, are deformable under compressive stress. Here we demonstrate that intralayer fracture toughness can be tailored via compositional design to make inorganic semiconductors processable by cold rolling. We report systematic ab initio calculations covering a range of van der Waals semiconductors homologous to InSe, leading to material-property maps that forecast trends in both the susceptibility to interlayer slip and the intralayer fracture toughness against cracking. GaSe has been predicted, and experimentally confirmed, to be practically amenable to being rolled to large (three quarters) thickness reduction and length extension by a factor of three. Our findings open a new realm of possibility for alloy selection and design towards processing-friendly group-III chalcogenides for flexible electronic and thermoelectric applications.

Room‐Temperature Wide‐Gap Inorganic Materials with Excellent Plasticity

“…Since 2018, a series of inorganic semiconductors, such as Ag 2 S [8] as well as Ag 2 (S, Se, Te) alloys [9][10][11][12] and 2D van der Waals (vdW) crystals of InSe [13,14] and others, [15][16][17] have been found to exhibit exceptional plastic deformability at room temperature, demonstrating that plasticity/ductility can be a crucial property of inorganic nonmetallic materials. High plasticity enables high-efficiency and low-cost manufacturing techniques (e.g., roller pressing, drawing, and forging) for various geometries with minimal fracture or waste.…”

Plastically Deformable Inorganic Semiconductors

“…Enlightened by the features of InSe, the combination of a high cleavage energy, a low slip barrier, and a small in-plane modulus is proposed as the criterion for predicting new plastically deformable 2D vdW materials. This helps filter several potentially plastic materials such as SnSe 2 , [26] CrCl 3 , [17] CrI 3 , [17] GaSe, [6,18,27] PbI 2 , [28] and CuInP 2 S 6 . [28] Very recently, considering both the interlayer and cross-layer slip and cleavage processes, Gao et al developed a high-throughput screening methodology and discovered more plastically deformable vdW crystals such as MoS 2 , GaSe, and SnSe 2 .…”